Selecting a connection in a network

ABSTRACT

A machine, such as a router (or other network appliance capable of filtering incoming packets), determines whether a packet is from a location that is likely to be capable of establishing an acceptable connection quality. If it is determined that an acceptable connection quality is unlikely to be obtained, the machine blocks the packet so that the connection is not established. If it is determined that the acceptable connection quality is likely to be obtained, the packet is received, and the connection is allowed. As a consequence of blocking packets from locations that are expected to have a poor connection, connections are not established with servers that will provide poor service and a poor user experience.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. Non-Provisionalapplication Ser. No. 16/726,713 (Docket #CA-8), entitled “SELECTING ACONNECTION IN A NETWORK,” filed on Dec. 24, 2019, by kin Kibet Fraser,which is incorporated herein by reference, is a continuation-in-part ofU.S. Non-Provisional application Ser. No. 15/168,213 (Docket #CA-4),entitled “SELECTING A CONNECTION IN A NETWORK,” filed on May 30, 2016,by kin Kibet Fraser, which is incorporated herein by reference, whichclaims priority benefit of U.S. Provisional Patent Application No.62/168,461 (Docket #CA-1), entitled “SELECTING A CONNECTION IN ANETWORK,” filed on May 29, 2015, by lain Kibet Fraser, which isincorporated herein by reference and also claims priority benefit ofU.S. Provisional Patent Application No. 62/197,399 (Docket #CA-2),entitled “SELECTING A CONNECTION IN A NETWORK,” filed on Jul. 27, 2015,by Iain Kibet Fraser, which is incorporated herein by reference.

FIELD

The current specification is related to selecting a connection in anetwork that will provide a satisfying user experience.

BACKGROUND

The subject matter discussed in the background section should not beassumed to be prior art merely as a result of its mention in thebackground section. Similarly, a problem mentioned in the backgroundsection or associated with the subject matter of the background sectionshould not be assumed to have been previously recognized in the priorart. The subject matter in the background section merely representsdifferent approaches, which in and of themselves may also be inventions.

A problem that arises when playing video games online (for example) isoften the connection is not very good, which leads to a frustratingvideo game experience. Similar problems may arise in choosing anappropriate server for a particular service when there are multipleservers available for providing the same or similar services, and theuser may be connected to a server with a bad connection for that usereven when other servers with better connections for that user areavailable.

Although some online video games include a mechanism for selecting aserver with a good connection, the mechanism does not work well andoften establishes a connection with a server that does not provide goodservice for that player. For example, players in the UK may findthemselves playing players in Mexico, despite there being playerslocated much closer by.

BRIEF DESCRIPTION OF THE FIGURES

In the following drawings like reference numbers are used to refer tolike elements. Although the following figures depict various examples ofthe invention, the invention is not limited to the examples depicted inthe figures.

FIG. 1 shows an example of a network in which the system may be used.

FIG. 2 shows a block diagram of an example of modules that may be storedin the routers of FIG. 1.

FIG. 3A shows a table of data that is used to construct some of theexamples that follows.

FIG. 3B in an example of a binary tree that may be used as a subnetaddress to subnet identifier index (e.g., as the address-to-identifierindex of FIG. 2).

FIG. 4A shows an example of the tree of FIG. 3B that may be searchedefficiently while compressed.

FIG. 4B shows an example of the tree of FIG. 4A, which has been furthercompressed, and which may also be searched efficiently while compressed.

FIG. 4C is a representation of an embodiment of a geographic locationindex.

FIG. 5A shows an example of a single bin of FIG. 4C.

FIG. 5B(1) shows a first tree, which represents an example of anencoding of a collection of location coordinates in which locationcoordinates that occur more often are encoded by shorter strings ofsymbols and location coordinates that occur less frequently are encodedwith longer strings of symbols.

FIGS. 5B(2)-5B(6) show different steps of a method of constructing atree that determines an encoding of a collection of sets of locationcoordinates in which location coordinates that occur more often areencoded by shorter strings of symbols and location coordinates thatoccur less frequently are encoded with longer strings of symbols.

FIG. 5B(2) shows step 1 of a method of encoding a collection of locationcoordinates of a set of subnets, which includes an initial partial treeand an initial list of identifiers of location coordinates of a set ofsubnets.

FIG. 5B(3) shows the next step, step 2, of a method of encoding acollection of location coordinates of a set of subnets, which includesan updated list of frequencies and an updated partial tree created fromthe updated set of frequencies.

FIG. 5B(4) shows the next step, step 3, of a method of encoding acollection of location coordinates of a set of subnets, which includesan updated list of frequencies and an updated partial tree created fromthe updated set of frequencies.

FIG. 5B(5) shows the next step, step 4, of a method of encoding acollection of location coordinates of a set of subnets, which includesan updated list of frequencies and an updated partial tree created fromthe updated set of frequencies.

FIG. 5B(6) shows the next step, step 5, of a method of encoding acollection of location coordinates of a set of subnets, which includesan updated list of frequencies and an updated partial tree created fromthe updated set of frequencies.

FIG. 5C(1) is an example of an index that may be used for looking up abinary representation of the location coordinates of a subnet ofinterest.

FIG. 5C(2) shows an index associating the binary representation of theindex of FIG. 5C(1) with the set of coordinates that are represented bythe binary representation.

FIG. 5D(1) is an example of another index that may be used for lookingup a binary representation of the location coordinates of a subnet ofinterest.

FIG. 5D(2) shows an index associating the binary representation of theindex of FIG. 5C(1) with the set of coordinates that are represented bythe binary representation.

FIG. 5E(1) shows an example of a location index having bit codes.

FIG. 5E(2) shows an example of an index for converting the bit codes ofFIG. 5E(1) into numerical values.

FIG. 6 is a flowchart of an embodiment of a method of selecting and/orblocking a connection.

FIG. 7 shows a flowchart of an example of the method of converting asubnet address into a subnet identifier, which may be used in part ofone of the steps of FIG. 6.

FIG. 8A shows a flowchart of an example of a method for implementing oneof the steps of FIG. 7.

FIG. 8B shows a flowchart of an example of a method for implementing oneof the steps of FIG. 7.

FIG. 8C shows a flowchart of an embodiment of a method of implementingone of the steps of FIG. 7.

FIG. 8D is a flowchart of an embodiment of a method of implementing twoof the steps of FIG. 6.

FIG. 9 shows a block diagram of an example of a router.

FIG. 10 shows an example of network interface module in the router ofFIG. 9.

FIG. 11 shows a block diagram of a console used in the system of FIG. 1

DETAILED DESCRIPTION

Although various embodiments of the invention may have been motivated byvarious deficiencies with the prior art, which may be discussed oralluded to in one or more places in the specification, the embodimentsof the invention do not necessarily address any of these deficiencies.In other words, different embodiments of the invention may addressdifferent deficiencies that may be discussed in the specification. Someembodiments may only partially address some deficiencies or just onedeficiency that may be discussed in the specification, and someembodiments may not address any of these deficiencies.

Although in this specification, the example of a players playing anonline game is often used, other types of users may be substituted forthe players and other services may be substituted for a game to obtaindifferent embodiments. Although the specification refers to packets anymessage may be substituted for a packet wherever the word packet appearsto obtain a different embodiment.

The Network of this Specification

FIG. 1 shows an example of a system 100 within which the current systemmay be used. System 100 may include a multiplicity of server systems 102a-n and a multiplicity of user systems 106 a-m having routers 108 a-mconnected to a network 110. In other embodiments, system 100 may includeadditional components and/or may not include all of the componentslisted above.

System 100 may be used for playing games and/or other purposes. Serversystems 102 a-n are a system of servers, which provide a particularservice to users, such as an online game. Any of server systems 102 a-nmay be referred to as hosts and are dedicated to a particular task oruser system performs that task for other users. In this specification,the term host refers to servers that are dedicated to a particular taskor user system that performs that task for other users. The that serversystems 102 a-n may be dedicated to the task of running the game and/ordedicated to another player in the game. For example, one of serversystems 102 a-n may be dedicated, as in the computer/host's only purposeis to be the server for the other players, or it may be a “listen host,”which is a host/computer server of the other players, and is also beingplayed on by one of the players. Effectively one of the players is thehost for one or more other players.

In an embodiment, all players connect to the host, and the host dictateshow the game is synchronized. Due to the host's position, the host hasthe highest influence on game quality and therefore the aim is to pick agood host. Some games may allow more than one host.

User systems 106 a-m are the systems used by users to access theservice, via a network. User systems 106 a-m may be any of a variety ofcomputing systems, such as smart phones, laptops, personal computers,and/or game consoles. In an embodiment, the user systems 106 a-m of oneof the users may be the server system, i.e. the host, and others of usersystems 106 a-m may connect to the user system of the user that ishosting the session and/or facilitating the connections. In anembodiment, the user system of one of the users may be the serversystem, i.e. the host, and other user systems may connect to the usersystem of the user that is hosting the session/facilitating theconnections.

Routers 108 a-m are used by user systems 106 a-m to connect to servers102 a-n to access the service. Although in FIG. 1 there is only onerouter for each user device, there may be several user devices sharingone router and any given user system may have a choice of multiplerouters for accessing the network. Routers 108 a-m are examples ofInternet nodes, and other network appliances may be used instead ofrouters 108 a-m as Internet nodes. In this specification, anywhere arouter is referred to, any Internet node may be substituted to obtainanother embodiment.

Routers 108 a-m intercept incoming and outgoing packets for a user andselectively filters the packets based on certain metrics. The filteringmechanism of routers 108 a-m may selectively decide whether to drop ornot drop packets. By dropping packets from hosts deemed to be of a badquality, the user is hindered or prevented from choosing that host,which may result in the user system continuing to search for a betterhost.

In other words, software may be installed in the routers 108 a-m toselect the best one of servers 102 a-n, or provide the user with a listof servers that have a higher quality connection from which the user maychoose, and to avoid establishing connections with servers that do nothave a good connection available. Subsequently, each of user systems 106a-m may receive a filtered list indicating the best server or indicatinga subset of servers that are currently the best servers that areavailable. In an embodiment, user systems 106 a-m may not get a list ofservers, but may just not connect to servers having bad connections, andwhen a server is found that is expected (based on a metric) to provide abad connection, the user's system may have to search again for anotherserver until a server with a good connection is found. In an embodiment,whether the user is given a list of servers or just keeps testingservers found, until a server with a good connection is found, dependson how the game handles not being able to connect to the bad host. In analternative embodiment, the user may make a selection that determineswhether a list of servers is provided or whether the testing of serverscontinues until one with a good connection is found. In an embodiment,the filters work in the same manner for different types of hosts, inthat the filters will filter the hosts regardless of the type of host.

Network 110 is the network used by user systems 106 a-m to accessservers 102 a-n. Network 110 may include a combination of many differentnetworks.

Accordingly, routers 108 a-m intercept incoming (from network 11) andoutgoing packets (sent via network 110) for players and selectivelyfilter the packets based on certain metrics (deciding whether to drop ornot drop packets). By dropping packets from hosts deemed to be of a badquality, it forces the game to at least not choose that host andpossibly to continue searching for better hosts (a packet may beintentionally—and automatically—dropped by automatically deciding to notsend an acknowledgement of the arrival of the packet even though thepacket in fact arrived). Stated differently, the protocol interprets adropped packet as a bad connection, and the router manipulates theserver and/or a client (or the protocol in use at the host and/orclient) by intentionally dropping packets. When the router determinesthat the connection is not likely to be a good connection, the routerintentionally drops a packet that would not otherwise have been dropped.As a result of the protocol used by the client and/or host, the clientand/or host interpret the dropped packet as a bad connection, and theclient and/or host cease to attempt to establish the connection. Inother words, modules (e.g., software or hardware modules) may beinstalled in the router to select the best server, or provide a list ofservers having a higher quality connection from which the user maychoose, and to avoid establishing connections with servers for which agood connection is not available (e.g., by dropping packets).Subsequently, an end user device may receive a filtered list indicatingthe best server or a subset of servers that are currently the bestservers available. The software for determining the quality of theconnection and/or for causing the dropping of the packets may be locatedin any of the network nodes instead of and/or in addition to beinglocated in the router.

Examples of Modules of the Routers of this Specification

FIG. 2 shows a block diagram an example of a unit 200 of modules thatmay be stored in the routers and/or servers of FIG. 1. Unit 200 mayinclude optional server selector 201 a, optional player selector 201 b,filter 201 c, update 201 d, and address-to-identifier index 202 havingsubnet address 204, mapping 206, and subnet identifiers 208. Unit 200may also include identifier-to-location index 210 having location-input212, mapping 214, and subnets 216. In other embodiments, unit 200 mayinclude additional components and/or may not include all of thecomponents listed above.

Unit 200 includes modules that ensure that the connections establishedfor completing a particular task or receiving a particular service (suchas playing an online game) are appropriate for the task being performedor service received. Unit 200 may be installed in any (or all) ofrouters 108 a-m and/or within server systems 202 a-n (on in routers ofserver systems 202 a-n).

Note that a software or hardware version of unit 200 may be used with asoftware router. For example, it is possible to configure a normalcomputer with two network cards and then install a software router onthe computer, so that the computer behaves like a router in that thatcomputer can forward packets from one device (e.g., the game console) toanother device (e.g., another router). The unit 200 (the filteringsoftware of the router of this specification) may be used with acomputer configured to behave as a router as well as with a router.

Also, some of user systems 106 a-n (e.g. some PC games) have a bad hostselection algorithm, as well. A version of unit 200 that runs on the PC(or any network appliance) may be installed on the PC that interceptspackets, and filters the packets, using one of the above metrics.Although a PC having unit 200 may be filtering packets, the PC is notnecessarily behaving as a router, because a PC does not forward packets.However, unit 200 may also be run on a computer (e.g., that runs a gameon a PC) to intercept and filter packets and select a host with anappropriate connection (in contrast, consoles do not allow software tobe run on them, other than games' and the console's proprietarysoftware, and so a proprietary version of the software would need to beinstalled).

In other words, a router of routers 108 a-m may act as gateway betweenthe user's device and the host. As a result of the router having aninterface accessible by a web browser, which may be any network capabledevice (any network appliance) having a browser—including the userdevice, may apply filtering settings that are applied to a version ofunit 200 that is installed at the webserver, without the need for thedirect installation of unit 200 on the user's device. Alternatively,unit 200 may be a plugin to an HTTP client running on one of user device106 a-n.

Since routers have a small amount of memory, a compression algorithm maybe used by unit 200 to store information on the router, which aids inrunning the algorithm. Additionally, because routers are limited inmemory and processing power, it is contrary to the current manner ofthinking to load and run filtering software on a router (or to installmost other software that is unrelated to the basic functioning of therouter), and then, in turn, use the software on the router to provideadditional features, options and software functionality to other devices(which commonly have more memory and greater processing power than therouter itself). Routers have at least three constraints that need to bedealt with simultaneously, which are a small amount of flash memory(which serves as permanent memory that persists when the router losespower), a small amount of RAM (which is used while the router isrunning) and a small amount of processing power. Because of the lowmemory and processing power, when the software is run on a router, theIP database must be compressed when saved, this specification recognizesthat it may be desirable for the database to remain compressed whenlookups are performed and it may be desirable to perform the lookups ina highly efficient manner, which is a difficult task as a result of thethree constraints of routers (a small amount of RAM, a small amount offlash memory, and low processing power).

The present software allows a selection of servers to be made that wouldotherwise not be possible or at least not be practical for the user tomake using the user device (e.g., a game box), the default options ofthe user's game, or the server provided by the game forum. As mentionedabove, although the software is described using the example of an onlinegame, the online gaming environment is just an example, and the softwaremay be used for selecting servers that will provide good connections,for other purposes, such as general internet use. In other words, inthis specification, although playing games over the Internet isdiscussed, as an example, the system of the specification may be usedfor other purposes in which there is a choice of servers available to auser to select from for providing the same or similar content and/oruser experiences, such as network TV and/or other network services. Inthis specification, any network may be substituted for the Internetand/or used in combination with the Internet.

The technology can work in the reverse direction, and a server may makesure that the clients connecting are clients that are likely to receivea high quality connection. Specifically, the game may have options forallowing a player to host the game session, with the player's consolebeing the server. For example, the player might choose to host a gamesession in the hopes that others will join the game session and playwith the player. Based on the player's proximity to other game players,the player might be a good host for the players that are nearby, and abad host for those far away from the player. However, the interfacebuilt into the game the player is playing may have no way ofdistinguishing between good hosts and bad hosts. Consequently, a playerin San Jose and a player in Tokyo might join a game session hosted by aplayer in San Jose, expecting to have an experience of the same quality,when the connection for the Japanese player might be very poor. Thesoftware may be used to filter out the players that are beyond a certaindistance or that for other reasons are expected to have a badconnection.

Optional server selector 201 a selects a server having a connection thatis of a quality appropriate for performing the task or receiving theservice. Optionally, the user systems 106 a-m and/or optional serverselector 201 a may include a list of acceptable servers that the usermay connect to for the desired service, and user systems 106 a-n and/oroptional server selector 201 a may include an algorithm for selectingone of the servers on the list.

On the user interface, when the user's device has its own software forchoosing servers for hosting the game, the optional server selector 201a may provide the user with two lists of servers. The first list havingthe servers chosen by the present software, and the second list havingthe servers chosen by the software on the user's device, but which werenot selected by the present software.

However, in an embodiment, the user systems 106 a-m may not get a listof servers from servers 102 a-n, but optional server selector 201 a mayjust cause the router (of routers 108 a-m) not connect to servers havingbad connections, and when a server is found that is expected (based on ametric) to provide a bad connection, the user's system (e.g., one ofuser system 106 a-m) may have to search again for another server until aserver with a good connection is found. In an embodiment, whether therouter or user system is given a list of servers or just keeps testingservers found, until one with a good connection is found, depends on howthe game or other service handles not being able to connect to the badhost. In an alternative embodiment, the user may make a selection thatdetermines whether a list of servers is provided or the testing ofservers continues until one with a good connection is found.

Optional player selector 201 b may select players of a game that arelimited to those that the user may establish a connection with that isexpected to be of an adequate quality for playing the game with.Optional player filter 201 b may be located on server system 202 a-n oron the routers of server system 202 a-n, but not on router systems 108a-m of user system 106 a-n. A user system that includes its own servermay include both sever selector 201 a (for situations when accessinganother server) and player selector 201 b (for when the user is usingtheir own server).

Filter 201 c filters out packets from players and/or servers that areexpected to not be of an adequate quality. Filter 201 c may include afilter that filters out connections based on the geographic locationthat the device of the player or server (in other words, filter 201 cmay be a geo-filter). Optional server selector 201 a and optional playerselector 201 b may use filter 201 c to select an appropriate serverand/or player. In an embodiment, filter 201 c accomplishes the tasks ofboth optional server selector 201 a and optional player selector 201 b,and optional server selector 201 a and optional player selector 201 bare not present.

For example, an ordinary computer or other internet appliance having aprocessor and memory may run a program causing the network appliance tofunction as a router, which may run filter 201 c for choosing serversthat are likely to provide a good connection.

The quality of the connection between one of server systems 102 a-n andone or user systems 106 a-m may be established (e.g., by filter 201 c)in any of several manners, such as geo-graphical distance, lineardistance, hop distance, ping time, and/or geographical locality, forexample. The geographical distance is the distance on the surface of theEarth from the player to the host. The linear distance is the totaldistance of the wires that make a route from the player to the host. Thehop distance is the number of routers between player and the host. Theping time is the time that it takes for a network (e.g. an Internet)packet to travel between the player and the host.

In at least some embodiments it may be impossible, or at best difficult,to determine the actual wire length from one router to another withoutsome external information, which may be not available. Similarly, in atleast some situations it may also be difficult to obtain a reliablemeasure for the hop distance.

The geographical location, used by filter 201 c, may be a geographiclocation of any shape outlining a region within which a good connectionis expected to be establishable, via network 110, which may correspondto how well the network infrastructure is maintained within a certainlocality, which in turn may correspond to a municipal or politicallyestablished region, such as within the limits of a certain city, town,county, province, country, block of countries, continent and/or otherregion. Alternatively, the geographic location may be within a circle ofa given radius from the user or within a polygon or other geometricshape within which the user is located. A shape may be determined on theworld (e.g., a polygon or a region for example Europe or North America)and packets from any hosts outside of that location are filtered out (nomatter the shape of the locations).

In one embodiment, the geographic distance from one of user systems 106a-m and a candidate for the server system (selected from server systems102 a-n) or candidate player is used as an indication that the serverwill have a good connection or whether the connection with the playerwill be adequate. In this embodiment, packets outside of the geographicdistance are inspected to determine the ping time. If the ping time isbelow a certain predetermined threshold, the packet is allowed to pass,because the packet is likely a packet from within the geographicdistance, but that was mislabeled. Alternatively, the ping time may below for other reasons, and the connection is allowed because the pingtime is low enough to facilitate a high quality user-to-host connectionthat would be comparable to a connection between users and a host withina geographic distance that is expected to result in a good connection.

Although the primary goal is to minimize the ping time, since minimizingthe ping time is not easy to do, and in some scenarios minimizing theping time cannot be done, a geo-filter, such as filter 201 c, may beused instead, because the geographic distance correlates well with pingtime. For example, a large geographic distance will usually mean a largeping time and vice versa. Alternatively, or additionally, the ping timemay be used as the only metric and/or in conjunction with other metricsfor determining whether to filter out a packet.

Some of user devices 106 a-m, such as conventional gaming consoles, maynot have the ability to freely download and install software, ordownload software at the user's discretion. Consequently, devices andgames that do not provide an option or feature may never be able toprovide a new option or feature, unless the maker of the device or themaker of the game expressly changes the device or changes the game. As aresult, if the user device or game does not allow the filtering of hostsby default, the user may never be able to rely on the device or softwarefor filtering hosts.

The filtering 201 c within units 200 of the routers 108 a-m provides theuser systems 106 a-m with (1) an ability to filter hosts that the usersystem or the user's game may lack, and (2) a web browser accessibleinterface, which allows the user to apply and/or modify various settingsfor filtering hosts or players. A web interface is just one way toprovide an interface to the user. In this specification, the term webinterface and user interface are used interchangeably and may besubstituted with one another to obtain different embodiments. Any userinterface that allows the user to control settings of the router and/orconsole may be used for the user interface.

Update 201 d provides a mechanism for updating the firmware of a routerthat is in use to provide additional software functionality andinterfaces that were not originally present on the router.

Implementation of the Geographic Filter of Filter 201 c

The geographic filter maps Internet Protocol (IP) addresses togeographic locations (longitude and latitude coordinates). Based on themapped location, the software determines whether packets sent orreceived from that IP address are allowed or dropped. Among otherthings, the algorithm maps IP addresses to locations as quickly aspossible, while keeping a small database.

IP addresses are usually allocated in blocks. All of the addresseswithin any given block are typically in the same data-center, andtherefore assigned the same location. By assigning all of the IPaddresses of any give block to one data-center and location, thealgorithm does not need to store IP addresses, but may instead store IPsubnets (a subnet may be a range of IP addresses, for example the rangeof IP addresses, 1.2.3.0-1.2.3.255 may be one subnet). In thisspecification, the term IP address is used interchangeably with the termsubnet, and one term may be substituted for the other to obtaindifferent embodiments, unless explicitly stated otherwise.

To map subnets to geographic locations at least two indexes may bemaintained.

An identifier-to-location index 202, which may be referred to as NetIdx,may be maintained, which the first index that may be maintained. Theidentifier-to-location index 202 is a fast IP subnet index. that mapseach subnet of interest to an identifier that labels the subnet (whichis later used to determine the region associated with the subnet),Subnet 204 is the input of the identifier-to-location index 202, whichaccepts a representation of a subnet address as an input. Mapping 206maps the subnet address of the input, subnet 204, to a geographiclocation. Geographic subnet identifiers 208 is a collection ofgeographic locations that are stored in a manner (e.g., a binary tree)that facilitates quick processing. Geographic subnet identifiers 208 arethe outputs of identifier-to-location index 202.

An identifier-to-location index 210, which may be referred to as aGeoIdx, may be maintained, which may be the second index that may bemaintained. The identifier-to-location index 210 is an index ofgeographic locations. GeoIdx may be the geographic index for the NetIdxand provides (or maps) the geographic locations that are associated withthe NetInx subnets. Subnet identifier 212 is an arrangement ofinformation, via which a geographic location corresponding to a givensubnet identifier may be generated. Subnet identifier 212 are the inputsof identifier-to-location index 210. Mapping 214 maps the subnetidentifier 212 of the input to the geographic locations as the output.Geographic location 216 is the output of the identifier-to-locationindex 210, which accepts a representation subnet identifier as an input.

To further elaborate, given a subnet, as input to the NetIdx, the NetIdxmay return an integer that is an identifier for the subnet, which whenused as input to the GeoIdx, the GeoIdx returns a location associatedwith the subnet. As explained above, the GeoIdx has a locationassociated with every subnet x in the NetIdx. Depending on theprogramming code used, a location that is associated with an IP address,x, is given by the expression,

GeoIdx(NetIdx(x))

In other words, the GeoIdx returns the geographic coordinates as output,when GeoIdx receives as input, the output of NetIdx, where the input ofNetIdx was the IP address x (which may be truncated by NetIdx to obtaina subnet address that is stored in the NetIdx).

Data Used to Construct an Example

FIG. 3A shows an index 300 of data that is used to construct many of theexamples that follows. Index 300 includes locations 302, frequency 304,latitude 306, longitude 308, and subnet IDs 310. In other embodiments,other data may be used for constructing a similar example, which mayhave other columns in addition to and/or instead of the columns of FIG.5B.

Locations 302 are a list of locations of a fictitious network from whichpackets are received at a router. Frequency 304 is the frequency interms of packets received during a particular unit of time. For example,frequency 304 may be computed as number of packets received from a givensubnet per hour. As another example, frequency 304 may be computed asnumber of packets received from a given subnet per month. Latitude 306is a latitude that is associated with the subnet, and longitude 308 is alongitude that is associated with a subnet. Since subnets have manylocations associated with each network address within the subnet, thelatitude 306 and longitude 308 cannot be coordinates of the subnet, butcoordinates that are roughly characteristic of the locations associatedwith the particular subnet address. Latitude 306 and longitude 308 maybe an average latitude and average longitude of all the subnet addressesfrom which packets are received or may be the center of the geographiclocation usually associated with the subnet of interest or some otherlatitude and longitude that is associated with the subnet that givessome at least rough approximation for the locations of users havingnetwork addresses with the particular subnet. Subnet IDs 310 are thesubnet IDs that have been found using compressed tree 500 b. All of thecomputations in this specification may be performed by machines such asrouters, servers, gaming consoles, machine that behaves as routers,servers, gaming consoles, or machines setting up the routers, theservers, gaming consoles, the machine behaving as routers, the machinesbehaving as gaming consoles, or the machines behaving as servers, forexample.

Subnet to Location Index (NetIdx)—an Example of a Binary Tree

FIG. 3B in an example of a binary tree 350 that may be used as a subnetaddress to subnet identifier index (e.g., address-to-identifier index202). Binary tree 350 may include nodes 1-19, which in-turn includesleaves 4, 9-11, 13-16, 18 and 19. Binary tree 300 also includes subnetidentifiers 1-10. Binary tree 300 may include additional componentsand/or may not include all of the components listed above.

Binary tree 350 may be used for a subnet to location index of a network.Binary tree 350 is relatively small for simplicity. An actual binarytree for representing subnets in the Internet would be much larger.Binary tree 350 may be constructed from index 300 by, for each subnetaddress, starting from the root node, starting with the first digit ofthe subnet address, reading the current digit of the subnet address. Ifthe current digit is a first value (e.g., 0), traversing to the leftchild, if the left child exists, and if the left child does not existcreate the left child. Similarly, if the current digit is a second value(e.g., 1), traversing to the right child, if the right child exists, andif the right child does not exist create the right child. However,moving forward, it is more convenient to label the subnets in the orderthat the subnets appear in the index.

Each node of binary tree 350 have no more than two children. Morespecifically, each node of binary tree 350 has either two children or nochildren.

A leaf is a node in a tree that has no children. A leaf can be thoughtof as being at the bottom of the tree. Representations of geographiclocations may be stored at each leaf.

Binary tree 350 is a tree full binary tree, since binary tree 350 hasnodes that either have two children or no children (the node with nochildren is leaf), and consequently no nodes have only one child.

In FIG. 3B the nodes are numbered in a specific order. The nodes arenumbered giving the nodes in the same row consecutive values with thelowest value at one end of the row, the values of the nodes increasemoving along the same row until the last node of the row, which has thehighest value. The first node of each row of the binary tree has thenext value consecutive to the highest valued node of the prior row.Thus, in binary tree 350, the root node is numbered as node 1, becausethe root node is the first node of the first row. Since the binary tree350 is a full binary tree, each row has double the number of nodes asthe non-leaf nodes of the prior row, and consequently there are only twonodes in the second row, which are numbered 1 and 2. Since both nodes 1and 2 are non-leaf nodes, the third has 4 nodes numbered 3, 4, 5, and 6.In the binary tree of FIG. 3B, the lowest valued node is the left mostnode and the highest numbered row is on the right. However, the lowestvalued node could be the right most node and the lowest numbered row ison the left, so long as each row is numbered consistently with the otherrows of the node. Also, since in practice the binary tree is neveractually drawn graphically, there is some arbitrariness as to the orderof the nodes, so long as the nodes are kept in the same order throughoutany computation and so long as it is possibly to draw a binary treesimilar to binary tree 350 that is consistent with the numbering of thenodes chosen. In other words, if one arranges the nodes with the firstnode as the root node as the first row and then moving down one row andarrange the nodes according to their numbers from left to right and thenrepeat, to find the location of each node and then what results shouldbe a binary tree.

Although the nodes are numbered with the first node being node 1 (inother words the values of the node numbers are incremented according tothe formula n_(i+1)=n_(i)+1 or n_(i)=i), the first node could be given adifferent number, such as 0 or another number. Also, although in FIG.3B, each node has a value that incremented by 1, at the expense of someof the compression and/or at the expense of some of the efficiency intraversing the tree, the increment be another number or be computedaccording to a different formula (in other words the values of the nodenumbers could be incremented according to the formula n_(i)=f(i). Forexample, one may use n_(i)=i+c or n_(i)=a*i+c).

In FIG. 3B, squares are used to represent leaves and circles are used torepresent nodes that have children. For example, node 1 has twochildren, nodes 2 and 3 as children, and therefore node 1 is depicted asa circle. Node 2 also has two children, nodes 4 and 5 as children, andtherefore node 2 is also depicted as circle. Node 3 has two children,and is therefore also depicted as a circle. Node 4 also has no children,and is therefore also a leaf and also drawn as a square. Node 5 has twochildren, nodes 6 and 7 as children, and therefore node 5 is likewisedepicted as circle, and similarly, nodes 6 and 7 each have two childrenand are therefore also leaves and depicted as circles.

NetIdx maps a list of subnets to integers that are identifiers ofsubnets (which are the input values for GeoIdx) that allow for fastlookups of location information, while keeping the location informationof the subnets in a compressed format. To achieve fast lookups, theinformation in NetIdx is stored in a tree structure. In an embodiment,an IP address is a 32-bit number. In other embodiments, the number ofbits in the address may be different (e.g., 64 bits or 128 bits). A treeis created in which every node represents a single bit in the IPaddress. The leaves of the tree have an index value for the geographiccoordinate of the subnet, represented by that IP address.

Binary tree 350 is not stored in the typical manner, because storing a32-bit tree in a conventional manner would require an enormous amount ofmemory. Instead the binary tree 350 is stored as a succinct tree (anexample of a succinct tree is described by Space-efficient static Treesand Graphs. Guy Jacobson. 1989, for example). To store the binary tree350 as a succinct tree, it may be desirable for the binary tree to be afull binary tree (and every node may have either 0 or 2 children—nonodes ever have only 1 child). To create a full binary tree, in binarytree 350, fake children (IP addresses that do not exist) may be addedthat point to random location-index values, for nodes that wouldotherwise have only one child. Optionally, all of the randomlocation-index values of the fake children may have the same value, sothat it is easy to identify the fake children.

Given a bitmap: a set of bits. The rank operator takes an index m in theset of bits and returns the total number of bits that are set to 1 andthat are less than or equal to m. e.g. rank(4)=3 for following set:

101100101.

Assuming that the IP addresses are 32 bits long, since binary tree 350is a succinct binary tree, binary tree 350 is traversed in constanttime, which is the time required for O(32) operations (the reason theorder of magnitude of the number of operations is 32 is because thereare at most 32 bits in the assumed length of the IP addresses), whichusing the rank operator is asymptotically O(1) operations assuming therank operator takes a constant amount of time per operation. In otherwords, since a subnet address (which is essentially a truncated IPaddress) is always less than 32 bits long, the time that is needed tolookup a particular subnet is always less than 32 times the time toinspect a particular node and determine which of the two edges of thetree to proceed along to arrive at the next child. The notation O(1) isoften referred to as “constant time” because the time to do a lookupdoes not change with the number of values stored in the database. So, ifthere are 2 billion or 4 billion IP addresses stored, the lookup timewould be the same so its referred to as constant time. See section 5 fora description of how the rank operation is implemented which includeshow the succinct tree membership map is encoded.

The leaves have an associated ID which is a natural integer. In anembodiment, the leaves are put in the order that that the leaves arefound doing a depth-first-search. The position of the leaves in theordered list is the ID associated with the leaf. The ID of the leafproviders a perfect hash that is used to index the geographic coordinateindex (a perfect hash has no collisions).

In another embodiment the leaves could be labeled in another fashion,such as from right to left on the binary tree. In FIG. 3B, the leavesare labeled from left to right along the tree, and thus node 4 is leaf 1(because node 4 is the leaf the furthest left), node 14 is leaf 2(because node 14 is the leaf that would be the furthest to left werenode 4 not present), node 15 is leaf 3 (because node 15 is the leaf thatis the closest to node 14 and that is on the left of node 14), node 9 isleaf 4 (because node 9 is the next leaf encountered when moving to theright from node 15 etc. The leaf labels are effectively subnet IDs.

In an embodiment, inputting the subnet identifier into the GeoIdx isperformed implicitly (as the leaf's position in the tree) and thereforetakes up no additional memory.

An Example of a Succinct Tree

FIG. 4A shows an example of a tree 400 a that may be searchedefficiently while compressed. Tree 400 a includes succinct tree 401,which includes node numbers 402 a, bits 404, original subnet IDs 405 andnew subnet IDs 406. Tree 400 a also includes bins 407, bin ranks 408,words 409, word popcounts 410, and sequence IDs 412. Tree 400 a mayinclude additional elements and/or may not include all of the componentslisted above.

Tree 400 a stores the binary tree of FIG. 3B in a compressed form andalso includes additional information that improves the efficiency withwhich the binary tree may be searched. Succinct tree 401 is a compressedversion of the full binary tree of FIG. 3B. A succinct tree is arepresentation of a full binary tree in a space efficient manner.Although tree 400 a is represented as an index having columns and rows,tree 400 a could be represented in other manners. For example, tree 400a could be stored in an array.

Node numbers 402 a are the node number from the binary tree 350 (FIG.3B). Bits 404 are a series of 1s and 0s representing whether a node is aleaf or a non-leaf. Specifically, the succinct tree 401 is arepresentation of the tree of FIG. 3B in which is represented a non-leafnode by ‘1’ and a leaf is represented by ‘0.’ In other embodiments,non-leaf nodes could be represented by ‘0’ and leaf nodes could berepresented by ‘1.’ Alternatively, non-leaf nodes could be representedby a first symbol, which could be any symbol, and leaf nodes could berepresented by a second symbol, which can be any symbol that isdifferent than the first symbol. Original subnet IDs 405 lists thesubnet IDs in the leafs of binary tree 350 (FIG. 3B). The choice of thesubnet IDs of binary tree 350 was chosen arbitrarily, so that one cansee how the subnets of binary tree 350 of FIG. 3B match the subnets ofthe index of FIG. 4A.

New subnet IDs 406 are identifiers for the subnets, which are orderedaccording to the order in which the subnets appear in tree 400 a.

To further elaborate, in the index of FIG. 4A, the first column, nodenumbers 402 a, contains the numerical label of each node, and the secondcolumn, bits 404 shows the succinct representation of the tree. In thecolumn bits 404, each non-leaf node, which was represented by a circlein FIG. 3B, and is given 1, and each leaf (which may be represented by asquare) is assigned a 0.

Succinct tree 401 of FIG. 4A converts the binary tree of FIG. 3B into abit map. One issue is how to navigate the bit map of FIG. 4A in anefficient manner. Determining the position of nodes and leaves may befacilitated by using the rank operator. The rank operator is defined as:

Rank(m)=the number of 1s up to and including position m. For example, inthe tree of FIG. 4A,

Rank(1) = 1, Rank  (2) = 2, and Rank(4) = 3.

Assuming that n_(i)=i, once one has the definition of rank, and if onefollows the convention of always placing the position of a child of nodem can be calculated by the following formula:

Left  Child(m) = 2 * Rank(m) Right  Child(m) = 2 * Rank  (m) + 1

When a 0 is reached, the node must be a leaf and therefore does not haveany children. The root node (the node at the top of the tree) is alwaysat position 1. If, however, n_(i)=f(i), then LeftChild(m)=f(2*Rank(f⁻¹(m))) and Right Child(m)=f(2*Rank (f⁻¹(m))+1).

As an example, referring to FIG. 4A, Rank(5)=4.

LeftChild(5) = 2(Rank(5) = 2(4) = 8  andRightChild(5) = 2(Rank(5) + 1 = 2(4) + 1 = 8 + 1 = 9.

Referring to FIG. 3B, one can verify that the left child is node and 8and the right child is node 9. Thus if one receives a subnet address101, for example, the first 1 in the subnet address 101 means that onefirst navigates the binary tree to the right. The next symbol of thesubnet 101 is 0, which means that next one next navigates the binarytree along the left branch. Then, the final symbol of subnet 101 is a 1,meaning that the last step is to navigate along the binary treefollowing the right branch. Performing that procedure (navigating right,left, and then right) using the tree of FIG. 4, navigating to the leftfrom the root node, Rank(1)=1, and so, RightChild(1)=2(1)+1=3, and soone navigates to node 3. Next, to find the left child of node 3, computeRank(3)=3 (adding all the bits up to node 3, based on the index of FIG.4A), and so LeftChild(3)=2(3)=6, bring the system to node 6. Next,navigating right from node 6, Rank (6)=5, and soRightChild(6)=2(5)+1=11. Reading across to the column, original subnetIDs 405, which has the subnet IDs, one can determine that node 11 hasthe subnet ID of 6. Then subnet ID 6 is used by identifier-to-locationindex 210 (which is the GeoIdx) to find a location to associate with thesubnet address 101. So using the rank, one can generate and traverse afull binary tree using a very space efficient bitwise notation.

Bins 407 are buckets in which the bits of succinct tree 401 have beendivided. In the example of succinct tree 401, each bucket has 6 bits.

Bin ranks 408 list the rank of the bit just before the beginning of abin. By storing the rank of the bit just before the beginning of thebin, the rank of a bit can be calculated by adding the stored rank ofthe bin to the number of bits from the first bit of the bin to thecurrent bit.

Words 409 are groups of bits within a bucket. Words 409 are the wordswithin bins 408. Each word of the words 409 is a group of bits withinone of the bins 407. By grouping the bits within a bucket into words,and storing the number of bits in each word, further saves computationtime be reducing the number of additions that need to be performed.Although in FIG. 4A, each bin has only two words, and each word has only3 bits, there may be any number of words in each bin and each word mayhave any number of bits.

Word popcounts 410 is the location where the popcount for each word 409is stored. The popcount is the number of bits in the word, and is usedto computer the rank.

Sequence IDs 412 are identifiers that identify the sequence of bitshaving the popcount listed word popcount 410.

The naïve approach of computing the rank of associated with a locationof interest would be to search from the left (which is the beginning) oftree 400 a to post m counting bits that are set to 1. Counting the bitsfrom the beginning of 400 a to current location has a search timeproportional to O(n) and is unacceptable in the router environment, forexample. The first simple solution is to use buckets. Every n bits,store the total number of bits set as equal to 1 at that point. Forexample, if the buckets have a size of 1000 and one wants to knowrank(5053) then one takes the pre-calculated rank for bucket 5, whichwill give rank(5000) then count the number of bits set to 1 up to bit 53and add the bits to get the total rank.

Computing the rank by placing the values of the locations into bucketsis a good solution in that the computation of the rank, and is fasterthan the naïve approach. However, bit counting itself is also slow.Regarding speeding up computing of the rank further, a bucket may bedivided into a bunch of words (each word may be a unit of bits, forexample 8 bit, 16 bit, 32 bit or whatever size one decides to choose).Instead of reading each bit in a word and counting the number of bitsset to 1, the number of bits set to 1 may be stored for each word, andthe stored number for each word may be referred to as the populationcount or popcount of the word.

By storing the popcount for each word and implementing the rankoperation, instead of having an O(n) searches—one search for each worduntil the last word of interest—to determine the contribution of eachword, the word search is only O(1) to find the last word of interest.For example, if the buckets include 32 bit words instead of doing 32 bitsearches, only one search in the last word of interest is needed,because the number of bits set to 1 and the prior words can bedetermined from the popcount (which has already been counted and arestored). In other words, although once the last word is found, there maystill be a need for further operations to read or otherwise determinethe bits set to 1 of that word, the number of operations to find thelast word is O(1).

A problem may be that once the final word is reached is how to determinethe number of bits set to 1 in the portion of the final word that is ofinterest, as in the prior example it was desirable to know rank (5053)with 32 bit words. Accordingly, the computation that may need to be doneis

RankBucket(5)+(popcount for words in bucket 5000 to location 5032)+?

The problem is how does one know how many bits there are set to 1 upuntil a location whose address ends in the middle of word. So, in theexample above, how many bits are set between 32 and 53? It is desirableto have a way of computing the number of bits set to 1 from the popcountback to the original bit sequence and count the set bits.

Recall a combination is a permutation where the order does not matter.To calculate the number of combinations of way of putting n objects intok slots, the following formula may be used.

Choose  (n, c) = n!/(n − c)!  c!

Notice that the choose function, which may be represented with just aC(,), the same as the formula for permutations but with additional 1/c!,because there c! permutations that have same items in a different order.Based on the function choose (n, c)=n!/(n−c)!c!, mentioned above, onecan define a function

${C\left( {n,m} \right)} = \begin{Bmatrix}{\frac{n!}{{\left( {n - m} \right)!}{m!}},} & {n \geq m} \\{0,} & {n < m}\end{Bmatrix}$

(where the convention of setting 0!=1 is used). C(n,m) represents thenumber of ways that m items can bit into n slots (where each slot canonly hold one item. Thus, if n<m, C(n,m), 0, because there are moreitems than slots. As an aside, some other use properties of C(n,m) areC(n,n)=1 and C(n,n−1)=n.

To create a bijection, or a bidirectional mapping between naturalnumbers and combinations, it is desirable to order the combinationssomehow. One way to do order the combinations is to have two rules,which are:

1) the first rule is that combinations values are always in descendingorder. So, for example in this convention, the sequence {4,3,1} isvalid, but the sequence {1,4,3} is not valid (another way of orderingthe values could be chosen, such as ordering the elements of thesequence from smallest to largest instead of from largest to smallest.one of the permutation repetitions

2) The second rule is that the order of combinations is lexicographic,that is the first element in the sequence is inspected first todetermine which elements are first and which are last, and then forseries with the same first element, the second element is inspected, andin general first inspect earlier element in the sequence to determinethat order, if the earlier element is the same, inspect the nextelement, to determine the order. For example, the four sequences beloware in lexicographical order.

{2,1,0}, {3,1,0}, {3,2,0}, {3,2,1}

Using the lexicographic order, a value, N may be computed, where Nrepresents the number of combinations that lexicographically precedesthe corresponding sequence.

By setting N to the number of combinations that lexicographicallyprecede the current sequence, for example, the above four sequence wouldmap to, that is would be assigned the following four N values:

{2,1,0}<->0 combinations before it

{3,1,0}<->1 combinations before it

{3,2,0}<->2 combinations before it

{3,2,1}<->3 combinations before it

The method above assignment is similar to assigning a number to eachword in a dictionary. If one wanted to assign a value to the word pond,‘pond.’ The first step is to find the number of words that start withletters less than ‘p’. Once the number of words starting have a secondletter less than ‘o’ and adds that to the running total of words before‘pond.’ Next, adds all the words starting ‘po’ but have a third letterless than ‘n’ to the total number of word preceding pond. Finally, oneadds all the word with the prefix ‘pon’ and letters preceding ‘d.’

Symbolically, a given word may be written as a sequence {C_(k), C_(k−1),. . . C₂, C₁}, k is the place number of the digit of the word. SinceEnglish words are arbitrary there is no computation for assigning thevalues to words, that can avoid counting all the words prior to the oneof interest. In contrast, the combinations are not arbitrary and can beassigned values in the following manner.

Let  the  sequence  C={Ct, Ct − 1, …  , C 2, C 1}

All of the combinations that share a prefix up until the symbol C_(k)can be represented as the sequence

C^(′) = {C_(t)^(′), C_(t − 1)^(′), …  , C₂^(′), C₁^(′)}

Where C_(t)′ . . . C_(k+1)′==Ct . . . C_(K+1), but C_(k)′ is differentthan C_(K)

In other word, sequences C and C′ share the same prefix, but differ atsymbol C_(k). Since the sequence C′ needs to be lexicographically lessthan the sequence C for us to count C′ as one of the sequences precedingC, it follows that C_(k)′<C_(k).

Since the symbols are stored in descending order, the suffix of C′ canonly be chosen from the symbols 0 to C_(k)′. Also, the number of slotsinto which the symbols 0 to C_(k)′ may be placed is k, because thesuffix of the sequence C is the slots having the systems running from C₁to C_(k). So the possible number of suffixes that may be chosen areC(C_(k), k).

If the formula C(C_(k), k) is applied to every possible prefix length,from 0 to t, the formula for N becomes,

N = C(Ct, t) + C(Ct − 1, t − 1) + … + C(C 2, 2) + C(C 1, 1)

Given a number N, and the number of elements in the series, thecorresponding series maybe computed as follows. From above, N isequivalent to

C(Ct, t) + C(Ct − 1, t − 1) + … + C(C 2, 2) + C(C 1, 1)

The formula for N suggests the following.

1) For all slots there is a number represented by C(c, i) where i is theslot number, and c is the unknown value of the element that occupiesthat slot.

2) Since combinations are stored in descending order C(C_(i), i),C(C_(i+k), i+k), it must be that C_(i)>C_(i+k), which means that thenumber of symbols to pick from must always be less than the number usedin the previous slot.

Consequently, to turn a number N back to a sequence, one may test thefirst slot values in reverse lexicographical order and calculate thenumber of sequences including the element before the current element.Using the dictionary analogy, assuming that all combinations of fourletters were words and that all words had four letters, given to computeN_(pond) to find what word that corresponds to.

There is no point in computing ‘z’=C(26,4), because necessarily, C(26,4)would be greater than N_(pond), because the lowest possible value ofN_(pond) is 0, and thus the highest possible value of N_(pond) isC(26,4)−1.

Next, compute ‘y’=C(25, 4), and since y>p, C(25,4) would be greater thanN_(pond), and consequently, the first letter could not be y.

Continuing eventually, one would compute ‘o’=C(15, 4), and would findthat C(15, 4) was the first value that was lower than N_(pond), and sosince there are C(15, 4) words that begin with o or an earlier letterthe first letter must be a p.

That is, all the letters above ‘p’ will have values greater thanN_(pond), and since ‘p’=C(16,4) represents all of the combinations of 4letters using any of the letters a-p, C(16,4) would include all of the pwords, and thus N_(pond)<C(16,4).

Since, N_(pond)>C(15,4), the first letter of the corresponding word mustbe p. Next, C(15,4) may be subtracted from N_(pond), because all of thewords before the letter p have been counted. In other words,N_(pond)=N_(ond)+C(15,4), where Nona is the numerical value that wouldbe associated with the sequence of letters for the fictitious word“ond.” To find the next letter, the process is repeated for Nona.However, since the words in this dictionary always have the letter thatcome later in the alphabet earlier in the word, the next letter must bea letter earlier in the alphabet than p. Also, now since there are only3 letters left, the second argument in the function C(C_(k),k) is 3 or kis now 3. Now a search begins for all combinations of letters that willfit into 3 places having a leading letter of ‘o’ or less. Starting theprocess again,

‘o’=C(5, 3) is necessarily greater than N_(ond), because C(15, 3) is thetotal number of words that can be made with the letters a-o, but thefirst possible value of N_(ond) is 0.

However, computing ‘n’=C (14, 3) yields a number that is less than Nona,which indicates that the next letter is o. Next N_(nd)=N_(ond)−C(14, 3)is computed, and N_(nd) a search the next letter is performed, repeatingthe above process. The above process is completed until all slots arecalculated.

If there are 2 bits set to 1 in a word that has 32 bits, then there areC(32,2) possible different combinations of 2 bits in a 32 bit word, andconsequently there are C(n, x)=n!/(n−x)!*x!)=32!/(2!*30!)=496 differentcombinations.

To determine which combination is the correct combination for a givenword, a natural number is mapped to each possible combination, thenatural number may be called the sequence identifier or offset. Thepopcount, the number of possible combinations (e.g., determined by theformula for the binomial coefficient), and the sequence identifieruniquely identify the value of the word. Optionally, to save memory, thevalues of the binomial coefficients are not stored, but are calculatedas needed and only the popcount and the sequence identifier are stored.Given the popcount, the number of possible combinations (which may becomputed when needed) and the word size, one can generate the originalbit sequence and therefore the bit count for any particular word.

Since the number of possible combinations is known as well, the numberof possible combinations can be stored in log2 (the number ofcombinations) bits instead of wasting memory on a greater number ofbytes, which may further improve the compression, while maintaining fastindexing. To reiterate, an index of the total rank so far is stored inbuckets. The buckets allow the software to jump to a bucket withouthaving to search through all of the entries before reaching the firstentry in the bucket of interest. Then, the software can search throughwords quickly by adding the popcount that is explicitly stored. Once theend of the word is reached, the original bit stream can be regeneratedby using the popcount and the offset with the combination mapping. Inother words, the popcount and offset can help regenerate the originalbit sequence of the last word, e.g.,

01001011

Having recomputed the original bit sequence of the last word, the naïveapproach of literal bit counting may be used. So, the rank(5) for thatbit sequence is 2, the rank of the sequence may be added to the totalrank so far which is

(Buckets rank)+(whole words in buckets up until last one's rank)+(thenumber of bits set to 1 in the word having the node between thebeginning of the word and the node of interest as determined by the nodenumber, the sequence identifier, and the popcount).

A contrived example may help in understanding how to reconstruct the bitsequence of the last word. For a word that is 3 bits long, the number ofcombinations can be summarized by popcount, as follows:

Popcount Combinations with their offset in bracket 0 000 (0) 1 001 (0),010 (1), 100 (2) 2 011 (0), 110 (1), 101 (2) 3 111 (0)In other words,

-   -   instead of storing 110, one can store an ordered pair of        numbers, one representing the popcount and one representing the        offset, such as popcount=2 and sequence identifier=1;    -   instead of storing 100, one can store an ordered pair of        numbers, one representing the popcount and one representing the        offset, such as popcount=1 sequence identifier=2; and    -   instead of storing 111, one can store an ordered pair of        numbers, one representing the popcount and one representing the        offset, such as Popcount=3 sequence identifier=0        The benefit is there is no need to know the original sequence.        Only the total number of bits set is needed, and it is only        necessary to read the popcount to know the total number of bits.        Instead of counting bits, as if the bits were stored in the        original sequence.

The only downside is when the last word is reached, and the rank insidethe word is needed, in that case, it is necessary to regenerate thesequence as shown in the bullet point examples. Then the bits can becounted by just scanning the sequence from left to right.

The rank operation allows fast rank calculations while maintaining acompressed bit stream. The rank operation is used extensively by thesuccinct tree used for the IP subnet fast lookup.

For example, if the popcount is for word is 2, there are three possiblebit sequences for a word with 3 bits, which are

011

101, and

110.

If the three sequences are given 3 ID numbers, such as 1, 2 and 3, thenit is not necessary to store the bit sequence. Once only needs to storethe sequence ID and the popcount. If the popcount is 1, then there arealso three possible sequences of 3 bits, which are

001,

010, and

100.

These three sequences may also be given sequence IDs 1, 2, and 3, andthen given the popcount, and the sequence number, the sequence isuniquely identified. I the popcount is 3 there is only one sequence ofbits possible, and so no sequence ID is needed. Similarly, if thepopcount is 0, there is only one possible sequence of bits and so nosequence ID is needed. For a three-bit word, keeping track of whichsequence ID and word popcount combination corresponds to which sequenceof bits may be relatively easy and may not take up much memory. However,it may be desirable to use larger words having 8 or 16 bits, forexample. In general, the sequence IDs can be computed using thefollowing conventions. Each place in the word is assigned a numericalvalue, starting with 0. So, the first place is 0, the second place is 1,and the third place is 2, and so on. The word may be represented by thenumerical values of the places having a bit set to 1.

Thus, the word 100 would be represented by {2} and 110 would berepresented by {2,1}. Similarly, the word 1101010 could be representedby {7,6,4,1}. Whether one writes {2,1} or {1,2}, it is the same word.The convention that will be followed is to always arrange the numbersrepresenting the word in descending order. So, the word 1101010 iswritten as {7,6,4,1} and is not written as {1,7,4, 6}, forepresents ther example. Returning to the sequence IDs, the sequence IDs are given bythe following formula,

Seq.  ID = C(C_(k), k) + C(C_(k − 1), k − 1) + … + (C₂, 2) + C(C₁, 1).

For example, although a sequence ID is not needed for the sequence 111,the sequence 111 is represented by {2,1,0}, and the Seq. ID for {2,1,0}would be C(2,3)+C(1,2)+C(0,1)=0.

The sequence 110 is represented by {2,1}, and the Seq. ID of{2,1}=C(2,2)+C(1,1)=1+1=2.

The sequence 101 is represented by {2,0}, and the Seq. ID of{2,0}=C(2,2)+C(0,1)=1+0=1.

The sequence 011 is represented by {1,0}, and the Seq. ID of{1,0}=C(1,2)+C(0,1)=0+0=0.

The sequence 100 is represented by {2}, and the Seq. ID of {2}=C(2,1)=2

The sequence 010 is represented by {1}, and the Seq. ID of {1}=C(1,1)=1.

The sequence 001 is represented by {0}, and the Seq. ID of {0}=C(0,1)=0.

Referring to FIG. 4A, since the first word has a popcount of 3, there isonly one possible sequence of bits (which is 111), and so no sequence IDis listed (because none is needed to regenerate the sequence of bits).The second word in FIG. 4A is 110, which is represented as {2,1}, and ascomputed above has a sequence ID of 2, as listed in the last column ofFIG. 4A. The third word in FIG. 4A is 011, which is represented as{1,0}, and as computed above has a sequence ID of 0, as listed in thelast column of FIG. 4A. The fourth word in FIG. 4A is 100, which isrepresented as {2}, and as computed above has a sequence ID of 2, aslisted in the last column of FIG. 4A. The fifth word has a popcount ofzero, which also only has one possible sequence of bits (which is 000),and so no sequence ID is listed (because none is needed to regeneratethe sequence of bits). The sixth word in FIG. 4A is 010, which isrepresented as {1}, and as computed above has a sequence ID of 1, aslisted in the last column of FIG. 4A.

To navigate the succinct tree based on the word popcount and sequenceID, one needs to be able to convert a sequence ID for a particularpopcount into a sequence of bits. One strategy is as follows, the numberof digits in the word is given by the word popcount. Incrementing theleading digit by one, increases the order of magnitude of the bitsequence in by an order of magnitude in base 2. If there are k digits,one finds the value C_(k) that give the highest value for C(C_(k),k)that is smaller than the sequence ID. For example, if the words have Wbits and the word popcount is P, then the lowest value C_(k) can have isP−1, and the highest value that C_(k) can have is W−1. For the firstdigit, k=P. The value of C_(P) is such that either C(C_(P)=W−1,P) isless than or equal to the Seq. ID or C(C_(P),P) is smaller than or equalto the sequence ID, while C(C_(P)+1,P) is less than or equal to thesequence ID or stated differently,

C(Cp = W − 1, P) ≤ Seq.ID  or C(Cp, P) ≤ Seq.  ID < C(Cp + 1, P).

The range of possible values for the first digit is W−1 to P−1. One canperform the search by first computing C(W−1,P). If C(W−1,P) is less thanor equal to the sequence ID, then the first digit is W−1 and the bitsequence can be represented by {W−1, . . . }. If C(W−1,P) is greaterthan the sequence ID, compute C(W−2,P) and determine whether C(W−2,P) isless than or

-   equal to the sequence number. If C(W−2,P) is less than or equal to    the sequence ID, then W−2 is the first digit and the bit sequence    can be represented by {W−2, . . . }. If not, the search continues.    After the first digit is found, a search for the next digit begins.

If the first digit is F, since the largest digit comes first and sincethere can only be one bit in any given place of the word, the next digitmust less than the first digit and can be any value from F−1 to P−2, andso one can start the search for the next digit at F−1 and computeC(F,P)+C(F−1,P−1) and determine whether that value is less than or equalto the sequence number. If it is, then the second digit is F−1, and thebit sequence can be represented by {F, F−1, . . . }. IfC(F,P)+C(F−1,P−1) is greater than the sequence number, then computeC(F,P)+C(F−2,P−1) and determine whether C(F,P)+C(F−2,P−1) is less thanor equal to the sequence ID. If it is, F−2 is the second digit, and thebit sequence can be represented by {F, F−2, . . . }. Otherwise, continuethe search for the next digit. If the second digit is S, then start thesearch for the third digit with S−1 and the range of possible values forthe next digit is S−1 to P−3.

So, one may try various values of Cp that setting C_(k) to(W−1−(P−1))/2=(W−P)/2. Then, for the first digit, k=P, and soC(C_(k),k)=C((W−P)/2, P) and then determine whether the sequence numberis smaller or greater than C((W−P)/2, P). If the value is smaller,

Although with just the first three columns of FIG. 4A, there is atremendous savings in memory, because the tree is represented as abitmap rather than a series of pointers, it is not necessary to storeevery bit and adding bits to compute the rank is not the most efficientmethod of computing the rank.

For example, if the words have 8 digits (or W=8), the sequence ID is 16,and the popcount is 4 (or P=4), then the representation of the word hasfour digits, and the first digit can be anything between W−1=7 andP−1=3. Starting the search for the first digit,C(7,4)=7!/(3!4!)=7(6)5*4!/(6*4!)=35, which is greater than 16. Nextcomputer C(6,4)=6(5)/2!=15, which is less than the sequence number.Thus, the first digit is 6, and the bit sequence can be represented by{6, . . . }. So the next digit can be any value between 5 and 2. So,computing C(6,4)+C(5,3)=15+(5*4/2!)=25, which is greater than thesequence number 16. Next, try to see if the next digit is 4,C(6,4)+C(4,3)=15+4=19, which is also greater than the sequence number16. Next, try C(6,4)+C(3,3)=15+1=16, which is the sequence number, andso the bit sequence can be represented to {6,3 . . . }. The next digitcan be any number between 3−1=2 and 1. ComputingC(6,4)+C(3,3)+C(2,2)=17, which is greater than the sequence ID is 16.So, it must be that the third digit is 1. Since the third digit is 1,the last digit must be 0, and so the bit sequence can be represented by(6,3,10), which means that the bit sequence is 01001011.

Note that once the first digit is determined to be 6, and C(6,4)=15,which differs from the sequence number by 1, then one can recognize thatC(C₃,3) must contribute just 1, and so since C(m,m)=1, it must be thatm=3=C₃. Then, the next two digits must contribute 0 to the sequencenumber, which means that C₂<2 and C₁<1, and since C₂>C₁, it must be thatC₂=1 and C₁=0. However, the method of the prior paragraph follows analgorithm that does not require any insight into the process and istherefore easier to encode. Different search algorithms could be used.For example, each digit could be performed by a variation ofNewton-Rapson search or of a bisection search, first testing a valuethat is halfway between the highest and lowest possible value of thedigit, until one determines a value for C_(k) such that,

C(C_(k), k) ≤ Seq.  ID  or C(C_(k), k) ≤ Seq.  ID < C(C_(k) + 1, k).

Returning to the example of receiving a subnet address 101, the first 1in the subnet address 101 means that one first navigates the binary treeto the right. Using the tree of FIG. 4A, to navigate to the left fromthe root node, the root node always has a bit value of 1, and so onecomputes Rank(1)=1. Then the right child of the root node is computedas, RightChild(1)=2(1)+1=3, and so one navigates to node 3, which isstill within the first word of the tree of FIG. 4A.

Next, since the current bit of the subnet address is 0, next one needsto navigate to the right. to find the rank of node 3, one reads the wordpopcount of the first word which is 3. A word with a popcount of threeonly has one possible bit sequence, which is 111, and since node 3 isthe last bit of this word compute (which is the first word), the rank isthe same as the word popcount or Rank(3)=3. Thus to navigate to theright from node 3, RightChild(3)=2(3)=6, and so the next node is 6.

The next digit (and the last digit) of the subnet address 101 is a 1,and so next one needs to navigate left from node 6. To compute the rankof node 6, since node 6 is the last node of the second word, the rank ofnode 6 is the sum of the word popcounts of first two words, which is2+3=5. However, ignoring the fact that count of the last bit of a wordis the entire word popcount, the bit sequence ID of the second word is2, and so the representation of the word bit sequence has two digits(the word popcount value is the same as the number of digits in therepresentation of the bit sequence). Using the notation above, W=3 andP=2 (where W is the number of bits in the sequence and P is the wordpopcount), and so the first digit can have the values of W−1 to P−1,which is the values of 3−1=2 or 2−1=1, and so if the first digit is two,C(2,2)=1, which is less than the sequence value, and so the first digitis 2. Since the next digit must be less than the current digit, the nextdigit can be a number W−2 to P−2, which is either a 3-2=1 or 2−2=0.Testing the higher of the two possible values first,C(2,1)+C(1,1)=1+1=2, which is the sequence ID, and so the bit sequenceis represented by {2,1}, which means that the bit sequence is 110, whichhas two bits set to 1, and so the rank is the sum of the words up untilthe current word, which is 3, plus the count of the current bit withinthe current word, which is 2 or the rank is 2+3=5. So, to navigate tothe right from node 6, Rank (6)=5, and so the right child of the 6^(th)node is RightChild(6)=2(5)+1=11.

Moving to the 11^(th) node, one determines the new subnet ID bydetermining the rank of node 11. Specifically, node 11 is in the secondword of the second bin, and so Rank(11)=(Bin Rank)+(popcount of firstword)+(bit count as determined by seq. No. and popcount of secondword)=5+2+0=7. Then since each node is either a leaf or not a leaf, andsince the bits set to 1 are not leafs, the new subnet ID=Node#−Rank(Node)=11−7=4. Next, the subnet ID of 4 is looked up in the SubnetID to location index.

An Example of a Compressed Succinct Tree

FIG. 4B shows an example of the compressed tree 400 b that may be savedaccording to one embodiment. Compressed tree 400 b includes, bin ranks408, word popcounts 410, and sequence IDs 412. Compressed tree 400 b mayinclude additional elements and/or may not include all of the componentslisted above.

Bin ranks 408, word popcounts 410, and sequence IDs 412 of FIG. 4B oftree 400 b were discussed in conjunction with tree 400 a FIG. 4A.

Unlike tree 400 a (FIG. 4A), compressed tree 400 b does not store thenode numbers, the subnet IDs, or the individual bits, and consequently,bits 404, original subnet IDs 405, and new subnet IDs, 406 are notpresent in FIG. 4B. To elaborate, the node numbers are computed whiletraversing the tree, and which bin and word the node is in and where thememory location is where the memory location is that stores theinformation associated with each bin and word can be computed based oneach the information about bin and word taking the same amount ofmemory, while the bit sequence can be determined using the wordpopcounts and the sequence ID, there is no need to store the actual bitsequences, node numbers or subnet identifiers, and so there is no needto store column 404,405 and 406 as part of the compressed tree, whichallows the tree to be further compressed.

A Geographic Location Index

FIG. 4C is a representation of an embodiment of a geographic locationindex 450. Geographic location index 450 may include bins 451AA-451NM,start 452 aAA-452 aNM, avg loc 454AA-454NM. In other embodiments,geographic location index 450 may contain other information and/orcolumns in addition to and/or instead of that shown in FIG. 4C.

Briefly, bins 451AA-451NM each contain information about a group ofsubnets. The subnets are grouped together so as to decrease the searchtime. To find a particular subnet, one first determines which bin thesubnet is in. Start 452AA-452NM are values of the subnet IDs (afterbeing converted to the geographic index coordinates, via index 420) ofthe first subnet in bins 451AA-451NM, respectively. To find a particularsubnet one first searches start 452AA-452NM to find a bin that has astart value that is less than or equal to the value of the subnet ID(after being converted to the geographic index coordinates, via index420), but that has a subsequent bin that has a start value that isgreater than the subnet ID of the subnet of interest. Once one finds thebin that has the subnet ID of interest, then a search is conductedwithin the bin found for the bin of interest. Avg loc 454AA-454NM arethe average geographic coordinates of the bin of interest.

To elaborate further, in an embodiment, the GeoIdx maps integers (theinput from NetIdx) to geographic coordinates efficiently in space andtime. In an embodiment, all subnets within a particular geographicalvicinity are given the same geographical coordinate. For example, in anembodiment, all subnets within the same 111 km vicinity are assigned thesame location coordinates. Consequently, many subnets may be in the samegeneral location geographically. For example, the geographicalcoordinate of a city may have significant repetition of coordinates. Byusing a Huffman tree (see “A method for the construction ofminimum-redundancy codes” 1952)[2] within which to store thegeographical location, the number of bits needed to record the labelsfor the geographical locations is less than were other methods used.Since the more frequently a symbol appears in the dataset, the fewerbits are used to represent that symbol, the Huffman algorithm achieves anear optimum compression. To elaborate, in a Huffman tree, coordinatesthat appear more frequently are encoded using fewer bits and vice versafor less frequent coordinates.

The downside of storing information in a Huffman tree (or for mostcompressions for that matter) is random indexing is lost. In otherwords, normally data is stored in bytes, so that for example if acoordinate takes up 8 bytes and if the 10^(th) coordinate is needed,then all that needs to do be done is to jump to the 8*10^(th) byte,which is the 80^(th) byte, read that byte, and compute the coordinate.However, with the Huffman tree, different coordinates require differentnumbers of bits (because the more frequent coordinates are representedby fewer bits and less frequent coordinates are represented by morebits). So, if the 10^(th) coordinate is desired, there is no way ofknowing how many bits there are until traversing all the coordinatesreading the different number of bits representing each coordinate untilthe end of the 9th coordinate is found. Then, after the start positionof the 10^(th) coordinate is found, the 10^(th) coordinate can be read.Consequently, if asked for coordinate x, the computer would have totraverse x−1 entries to reach x. Therefore, indexing would be O(n) whichis unacceptable in this context.

To compensate for encoding of the coordinates using different lengths ofstrings of bits for coordinate sent that occur more frequently, thecoordinates corresponding to the subnets are divided into buckets of acertain size, for example 1000 sets of coordinates (corresponding to1000 subnet IDs). In this specification, the terms bin and bucket areused interchangeably. Either term may be substituted for the otherwherever the terms bin or bucket occur. Bins 451AA-451NM are examples ofbuckets of location to subnet index 210. Start 452AA-452NM are thestarting coordinates of bins 451AA-451NM. Optionally, there may beanother index that stores the starting position for each bucket (whichis start 452AA-452NM). For example, if the 3030^(th) entry is required,the software would jump to the 3^(rd) bucket and therefore the 3000^(th)entry. Then, within the third bucket only 30 entries need to besearched. Although the number of operations required is still in theorder of O(n), the use of the buckets can reduce the number of timesthat the worst case, size n, occurs.

Avg loc 454AA-454NM are the averages of the coordinates of the locationsin bins 451AA-451NM. Storing the location coordinates in buckets alsoprovides an opportunity to improve compression. For each bucket theaverage location of all coordinates in the bucket (avg loc 454AA-454NM)is computed. Then, the coordinates of the average locations of thebuckets are stored relative to the origin of the bucket. Using valuestaken relative to the origin of the bucket results in the coordinates ofall buckets being shorter in length, because the coordinates are allrelative to an origin instead of being spread out over the entire world.In other words, the values of the latitudes range between −90 and 90,and the values of the longitudes range between −180 to +180, whichincludes a large spread in the possible values of the coordinates.However if a group of coordinates are placed in a bucket, and thecoordinates of the center of the locations stored in the buckets iscomputed (which is the average of all of the coordinates in the bucket),then if the coordinates within the buckets are stored in a format inwhich each coordinate of the bucket is relative location to the middlepoint, then most likely the locations will have a smaller range ofvalues, (e.g., −30 to 30), because each coordinate is more likely to benear the middle of the bucket (and the number of locations in eachbucket is fewer than the entire set of coordinates). Optionally, thecoordinates chosen to be within each bucket may be chosen to be within acertain geographical region, which further increases the likelihood thatthe range of values of the coordinates will be less than were thebuckets not used. Since the length of each coordinate is shorter, eachcoordinate takes up less memory (improving the compression), and may betraversed more quickly. Using location coordinates, for the buckets,that are relative to an origin, increases the frequency of coordinatesof servers that are repetitious of one another (as a result of differentusers using the same servers). For example, if there are many morecoordinates closer to the origin, coordinates of 1,1 are far morelikely. The increased frequency of repeated coordinates simplifies theHuffman tree, so that the Huffman tree may require less memory to store.In another embodiment, the average coordinates of the bin maybe computedafter removing outliers from the average. In another embodiment, anothervalue other than the average coordinates may be computed and used as anoffset that is subtracted from the coordinates prior to storing thecoordinates that minimizes the memory required for storing the locationcoordinates. In practice, using the average coordinates from the bucketsas the offset results in about a 10% reduction of memory.

In summary, given an integer index x from NetIdx, the bucket is found bysearching for a bucket within which that index is located. For example:

bucket = x/number  of  entries  in  the  bucket

Then the entry in the bucket is found by searching the entire bucketuntil the address is found. Then the bucket's origin is plugged in tothe formula

coordinate=(the bucket origin)+(the relative coordinate position withrespect to the center of the bucket),

which gives the coordinates of the absolute position on the globe, whichis the location of the IP address.

One Bin of a Location Index

FIG. 5A shows an example of a single bin 500, which is an embodiment ofthe buckets of the Huffman tree. Bin 500 includes start bin coordinates502, average bin coordinates 504, local bin coordinates 506, and wordsa-n. In other embodiments, bin 500 may include additional componentsand/or may not include all of the components listed above.

Start bin coordinates 502 are the coordinates of the beginning of thebin, which may be start 452AA-452NM (FIG. 4A).

Bin 500 may be any of the bins of FIG. 4A and may be any bucket of theHuffman tree. Start coordinate 502 of bin 500 is the first bit of thebin 500, which may be the start coordinates, start 452AA-452NM, thatcorresponds the same bin as bin 500. The rank of the locationcorresponding to start coordinates 502 are stored in association withthe start coordinates 502, so that the rank of the bin does not need tobe computed each time the rank of the location of interest is desired.Average bin coordinates 504 is the average of the global coordinates ofthe locations within bin 500, which may be the average coordinates, avgloc 454AA-454NM, that corresponds the same bin as bin 500. Local bincoordinates 506 are the local coordinates of bin 500. In the localcoordinates of bin 500, the value of the average of the coordinates areeach zero, the global coordinates of any location within bin 500 may becomputed by adding the values of global coordinates of the averagecoordinate bin coordinates 504 to the value of the local coordinates ofthe location of interest that is within bin 500. The local coordinatesof the locations within the bin and the global coordinates of theaverage location of the bin are stored rather than the globalcoordinates of each location in the bin to save memory. A nodeidentifier of the node of the succinct tree of the tree index 300 isstored in association within the coordinates of each location within bin500. Although the location of a subnet could be determined by storinglocation coordinates at each node of tree index 300 based on the nodeidentifier alone, the space required would be significantly larger.

Method of Setting Up Subnet-to-Location Index

FIG. 5B(1) shows a first tree, which represents an example of anencoding of a collection of location coordinates in which locationcoordinates that occur more often are encoded by shorter strings ofsymbols, and location coordinates that occur less frequently are encodedwith longer strings of symbols.

It is desirable that the geographic location index be stored incompressed manner that may be searched efficiently. The geographiclocation of each subnet is represented by a bit code. Regions with moreInternet traffic tend to have higher populations of users and moresubnets. Since the geographic coordinates are intended to represent asubnet, which includes a larger region than just one point there is noreason to store precise geographic coordinates for each subnet. Forexample, one the first three the geographic location coordinates may bestored or all of the geographic coordinates may be rounded off to wholeintegers. The result is that regions that have a lot of Internet trafficwill have multiple subnets with the same geographic coordinates, and thesame geographic coordinates may appear multiple times in in thegeographic index. Consequently, the geographic index may be compressedby encoding geographic locations that occur more often with short bitsequences.

For example, assume that there are 13 subnets, but, at least to theprecision that the geographic coordinates are recorded, there are only 4unique pair of geographic coordinates, a, b, c, and d, which appear inthe sequence, “abbbbbcdccbba.” For example, perhaps the geographiclocations of these four subnets are given by a=(74, −163), b=(181,0)c=(100,40), and d=(0,0). The frequency in of each symbol a, b, c, d is:

$\quad\begin{matrix}{{{f\lbrack a\rbrack} = 2}{{f\lbrack b\rbrack} = 7}{{f\lbrack c\rbrack} = 3}{{f\lbrack d\rbrack} = 1}} & \;\end{matrix}$

Storing a file in an uncompressed manner would represent each symbol asa fixed length binary sequence. For example:

a = 00b = 01c = 10d = 11

Then a file could be represented as a sequence of binary codes so theabove would be

a b b b b b c d c c b b a 00 01 01 01 01 01 10 11 10 10 01 01 00,

which uses 26 bit to encode the sequence of 13 symbols. However, if thelength codes for each symbol is different, the file can be compressed bystoring more frequent symbols with shorter binary codes and lessfrequent symbols with longer binary codes. For example, if

a = 001b = 1c = 01d = 000

then

a b b b b b c d c c b b a 001 1 1 1 1 1 01 000 01 01 1 1 001,

which uses 22 bits to encode the same sequence of 13 symbols.

For variable length encoding, it is desirable that the prefix of eachbinary representation be different from any binary representation havinga different length (although binary representations of the differentlengths may have the same prefix), so that a given symbol that has agiven sequence of bits as a prefix is not confused with another shorterbinary sequence that is the same as the prefix, and thereby simplifydecoding a sequence of symbols. So as mentioned above, the sequence

a b b b b b c d c c b b a 000 1 1 1 1 1 01 001 01 01 1 1 000

is compressed to being 22 bits long using the encoding of a=000, b=1,c=01, and d=001, whereas the uncompressed file was 26 bits long. Thecompression only results in a modest savings, but that is only becausethe example file is already small. In larger files with symbolsoccurring in commonly occurring frequencies, the savings aresignificantly greater. An encoding of symbols with higher frequencies isused to store the representations of the locations. So, instead of along list of codes in which each symbol representing latitudes andlongitudes have a fixed length, the representation of each symbol has adifferent length. Consequently, popular locations, such as New York willbe stored in significantly fewer bits than unpopulated areas, such asBermuda.

FIG. 5B(1) shows a tree representing the above encoding. In FIG. 5B(1),in each node are a number indicating the frequency of the symbolfollowed by a colon and then the symbol. Each of the children of anynode sum to the frequency of the parent. The square nodes are leafs, andcorrespond to the actual subnets. The circular nodes are inserted, andthe node identifiers are followed by an asterisk to indicate that thosenodes were derived and inserted, and are not part of the original set ofdata. A method for constructing trees, such as in FIG. 5B(1) isillustrated in the next example.

An Embodiment of an Encoding Method

FIGS. 5B(2)-5B(5) show different steps of a method of constructing atree that determines the subnet IDs for the subnet-to-location index forthe example of FIGS. 3A-4B. Continuing with the example FIGS. 3A-4B, asshown in FIG. 5B(2), the subnets have the following frequencies,

SUBNET ID FREQUENCY 1 1 2 1 3 1 4 1 5 6

FIG. 5B(2) shows step 1 of a method of encoding a collection of locationcoordinates of a set of subnets, which includes an initial partial treeand an initial list of identifiers of location coordinates of a set ofsubnets. Included in FIG. 5B(2) is the original table of the frequenciesand a partial tree created from the first two elements of the table. Thelist of elements is sorted by frequency. To create the partial tree, thetwo elements having the lowest frequencies (subnet 1 and 2) are used asleaves at the bottom of the tree. A parent node 6* is created for thetwo leaves, and the frequency of the parent node is assigned a frequencythat is the sum of the children's frequencies, 2.

FIG. 5B(3) shows the next step, step 2, of a method of encoding acollection of location coordinates of a set of subnets, which includesan updated list of frequencies and an updated partial tree created fromthe updated set of frequencies.

The updated table was created by removing the two elements, having thetwo lowest frequencies (subnets 1 and 2), which were used for creatingthe partial tree of step 1, and adding the new parent node to the listof frequencies at a point in the list so as to keep all of the elementsof the table listed in frequency order.

As part of step 2, to create the updated partial tree of step 2, theprocess is repeated and the two elements with the lowest frequencies inthe revised list of step 2 (elements 3 and 4) are assigned a parenthaving a frequency that is the sum of the frequencies of the two lowestfrequency elements (resulting in the partial tree of step 2), which inthis example is made of two disconnected partial trees having a parentnode, 7*, that also has a frequency of 2.

FIG. 5B(4), shows step 3. Next, in step 3, the process is againrepeated, and the table is again updated by removing the two lowestfrequencies (subnets 3 and 4) of the table of step 2, and adding theparent node of step 2 (7*) to the table, resulting in the table of step3. After the assigning of the two lowest of step 3 a parent (8*), thetree becomes the tree of step 3.

FIG. 5B(5) shows the next step, step 4, of a method of encoding acollection of location coordinates of a set of subnets, which includesan updated list of frequencies and an updated partial tree created fromthe updated set of frequencies.

FIG. 5B(6) shows the next step, step 5, of a method of encoding acollection of location coordinates of a set of subnets, which includesan updated list of frequencies and an updated partial tree created fromthe updated set of frequencies. After step 5, the revised list ofelements will just have one element node 9*, which has a frequency of10. However, since there is only one element in the list, that elementis the root node, and the process is finished. Using the tree of step 5,each set of location coordinates can be assigned a binary code byassociating a first value (e.g., 0) with a left branch and a secondvalue (e.g., 1) with a right branch. Then for leaf, the tree istraverses from the root node to the leaf to determine the bit code thatrepresents the subnet of that leaf.

There are other methods at arriving at the same of a similar encoding.For example, one could order all the sets of coordinates according tofrequency and then starting with the most frequent set of coordinatesassign it a value using as few digits as possible. However, if a prefixof a current set of bits is the same as an entire prior code for a priorset of coordinates, skip that set of bits and assign the current set ofcoordinates the first sequence of bits that does not have a prefix thatis the same as a code that was already used to represent a prior set ofcoordinates. As another option, one may iteratively minimize a function,which is the sum of the products of the frequency that a particular setof coordinates occurs times the number of bits used to represent thatfrequency. For each bit string length (l) there are 2′ possible bitstrings less the number of combinations that are not available as aresult of the prefixes of those combinations already being in use byshorter bit strings. For any given bit string length, the number ofcombinations that are not available may be computed, because each time aparticular bit string of a particular length (l) is assigned as anencoding for a network coordinate, two bit strings of length (l+1) withthe same prefix are now unavailable, the four bit strings of length(l+2) with the same prefix are now unavailable, and the 2^(n) bitstrings of length (l+n−1) with the same prefix are now unavailable.Also, if at length l, as a result of prior choice at shorter stringlengths, currently there are m strings available, but only n was used,then at string length l+1, there will be 2*(m−n) strings available, andso at each iteration before changing the number of bit strings in use,one may need to check that the choice does not cause another choice ofhow many bit strings of the another length to now, to no longer bepossible, and skip that choice of combination of lengths of bit stringsto use. The longest string of bits that one would ever want to use hasas many bits as there are elements being encoded. One may cycle throughall of the possible combinations of bit lengths to use for encoding eachfrequency, discard those combinations that are not possible, compute thenumber of bits needed for each combination (by computing the sum of theproducts of the frequency that a particular set of coordinates occurstimes the number of bits used to represent that frequency), and find thecombination that uses the fewest number of bits to encode the index thatassociates the subnet IDs with location coordinates. After oneiteratively determines how many bit strings to use for each length so asto minimize the sum of the products of the frequency that a particularset of coordinates occurs times the number of bits used to representthat frequency, the bit strings of each length may then be chosen. Aslong as one has a way of assigning more frequently occurring sets ofcoordinates codes that use fewer digits than less frequently occurringsets of coordinates, while ensuring that each set of bits does notinclude a prefix that is identical to a shorter length code that wasalready assigned to another set of coordinates, the resulting set ofcodes for the set of coordinates is acceptable.

An Example of an Embodiment of a Geographic Location Index

FIG. 5C(1) is an example of an index 550 that may be used for looking upthe location index coordinates of a subnet of interest. Index 550 mayinclude bins 552, subnet IDs 553, start of bin 5554, and a bit code 556.In other embodiments, index 550 may contain other information and/orcolumns in addition to and/or instead of that shown in FIG. 5C(1).

Index 550 is an example of a geographic index, which corresponds to theexamples of FIGS. 4A, 4B, 5B(6). The combination of index 420 andgeographic index 550 form an example of the identifier to location index210, and defines an example of the mapping 214 of FIG. 2.

Bins 552 are buckets that the information stored about the subnets havebeen divided into. The number of subnets in each bin could be thedifferent from other bins. Alternatively, all of the bins may haveinformation about the same number of subnets. Using bins 552 one canfirst locate the bin into which the information about the subnet ofinterest is locations and then search within the bin found for thesubnet of interest, because searching the first location-indexcoordinate of the bins is quicker than inspecting all the location-indexcoordinates in sequence until the location-index coordinate of thesubnet of interest is found, which speeds up the search. In FIG. 5D, aheavy line is used to indicate the division between bins.

Subnet IDs 553 are the subnet IDs that were found using tree 400 b ofFIG. 4B.

Start of bins 554 is the location-index coordinate of the first subnetin each bin correlated with the information about the corresponding bin.To search for a particular subnet ID, one may first search for the binjust prior to the bin whose start of bin is greater than the subnet IDof interest, and the bin just prior to the bin whose start of bin isgreater than the subnet ID of interest is the bin of interest.Alternatively, the last subnet ID of the bin may be stored/listedinstead of (or even in addition to) the first subnet ID of the bin, andthen one may search for the first bin that has a subnet ID whose lastsubnet ID is greater than the subnet if interest to find the bin havingthe subnet ID of interest. After finding the bin of interest, the bin issearch for the subnet ID of interest.

Bit code 556 is the bit code that is used to represent the locationcoordinates of the subnets having the corresponding subnet ID. Bit codes556 uses shorter sequences of bits to represent sets of coordinates thatoccur more frequently in index 550 and longer sequences of bits torepresent sets of coordinates that occur less frequently in index 550.Additionally, the values of the bit codes have been chosen that none ofthe prefixes of the longer bit codes are identical to the shorter bitcodes.

FIG. 5C(2) shows an index associating the bit codes of index 550 withthe set of coordinates that the bit code represents. Index 550represents (and is based on) the same encoding of the locationcoordinates as represented by the tree of FIG. 5B(6). Index 550 may bestored and searched as a binary tree, for example. In the fictitiousexample of the network of FIG. 3A, when a packet has a subnet address isreceived, the subnet address is read and then input into the index 400 bof FIG. 4B, which yields a subnet ID. Then the subnet ID found is lookedup in the index 550 of FIG. 5C(1), which yields a bit sequencerepresenting a set of location coordinates. Then, the bit sequence foundis looked up in an index represented by the tree of FIG. 4B or index550, to determine the location coordinates of the subnet of interest.

An Example of Another Embodiment of a Geographic Location Index

FIG. 5D(1) shows index 560, which is another example of location isanother example of a location index. Similar to index 550, index 560includes location-, bins 552, subnet IDs 553, start of bins 554, bitcode of location coordinates 556, bit code of avg. loc. 558. In otherembodiments, index 550 may contain other information and/or columns inaddition to and/or instead of that shown in FIG. 5D(1).

Similar to index 550, index 560 is an example of a geographic index,which corresponds to the examples of FIGS. 4A, 4B, 5B(6). Thecombination of index 420 and geographic index 550 form an example of theidentifier to location index 210, and defines an example of the mapping214 of FIG. 2. Bins 552, subnet IDs 553, and start of bins 554 werediscussed in conjunction with FIG. 5C(1).

Bit code of coordinates 556 of codes representing a set of coordinates,where each set of coordinates has an offset (e.g., the average of thecoordinates of that bin) subtracted from the value of the coordinates.By subtracting off the average, the value of the coordinates of the bin,magnitude of the coordinates of the subnets is smaller and therefore canbe represented with fewer bits. Also, there may be fewer sets ofcoordinates that need to be coded, because some of the sets ofcoordinates with larger magnitudes may no longer be present.

Bit code of avg. loc. 558 is the bit code of the value of the average ofthe of the location coordinates of all the subnets of the bin. Tocompute the location coordinates of a give subnet, the locationcoordinate corresponding the bit code of the avg. loc 558 for the binhaving the information about subnet is added to the location coordinatescorresponding to the bit code of the location 556.

FIG. 5D(2) shows an example of an index for converting the bit codes ofFIG. 5D(1) into location coordinates. The index of FIG. 5D(2) may berepresented as a binary tree, for example, for a fast lookup. In FIG.5D(2), the first four location coordinates occur more frequently (twice)than the remaining location coordinates, which only occur once. The lastthree location coordinates are the average location coordinate of thethree bins of the index 560.

As one can see by inspecting FIG. 5D(2) and comparing the bincoordinates to the corresponding longitude and latitude of FIG. 5D(2)with the longitudes and latitude of the index of FIG. 5D(1), themagnitude of the values of the within bin longitudes and latitudes ofFIG. 5D(2) tend to be smaller than the global longitudes and latitudesof the index of FIG. 5D(1), and therefore tend to require fewer bits torepresent and require less memory (in practice storing the within bincoordinates leads to about a 10% further reduction in memory needed tostore the geographic index). Although difficult to see without the useof hindsight, one possible reason for the savings in memory needed tostore the longitude and latitude when using within bin coordinates isthat even when the locations in the same bin are very far a part, suchas Tokyo and New York, many of the subnets in the bin may havelongitudes that are close to one another and/or many of the latitudesmay have close values and therefore storing the average values for thebin as a whole and storing the within bin longitude and latitude maylead to a savings in space. Also, although it did not occur is thesimple examples of this specification, in a realistic set of coordinatesof subnets, as a result of the averaging, some of the larger possiblemagnitudes of location coordinate may not even occur, and there may befewer sets of location coordinates in the entire set of locationcoordinates used to represent the subnets, allowing fewer bits to beused for representing several, possible all of the locations coordinatesets. However, use of the within-bin longitude and latitude instead ofthe global longitude and latitude is optional. Similarly, the use oflongitude and latitude or GPS coordinates in optional any othercoordinate system may be used instead.

Returning to the example of FIGS. 3, 4A, 4B, 5B and 5C, havingdetermined that the subnet having subnet address 101 corresponds tosubnet ID 4, using index 560, searching the start of bins 554, (thestart location indexes of the bins), the first bin starts with locationindex coordinate 1 and the second bin starts with location indexcoordinate 3, and so location index coordinate 2 is in the first bin.Searching the first bin, subnet 4 has a bit code of 110 representing thewithin bin coordinates, which from index of FIG. 5D(2) has within bincoordinates of (−31, 3), while the average of the coordinates for thebin as bit code 0101, which (from FIG. 5D(2)) corresponds to the averagebin coordinates of (72, −77). Adding the bin coordinates (−31, 3) to theaverage coordinates of the bin (72, −77), one obtains the globalcoordinates of (41, −74) (which is New York), which can be used tocompute the distance from the router to the subnet address that sent thepacket. In another embodiment, one could first assign each set ofcoordinates an integer value (e.g., in which the more frequentlyoccurring set of coordinates are assigned lower values), which may bereferred to as coordinate identifiers, and the use an average of valuesof the coordinate identifiers instead of the average bin coordinates.Then the resulting values of the coordinate identifiers may be encodedusing larger bit sequences for representing the more frequentlyoccurring coordinate identifiers and longer bit sequences for the lessfrequently occurring bit sequences. However, then either an index needsto stored correlating the coordinate identifiers to the locationcoordinates, or an algorithm needs to be stored and run for convertingthe coordinate identifiers to location coordinates, whereas, although inthe examples given in this specification, although it may be convenientto use coordinate identifiers for the method illustrated in FIGS.5B(2)-5B(6), after the bit code is computed for each set of coordinates,the coordinate identifiers are no longer needed, and may be discarded.

An Example of Another Embodiment of a Geographic Location Index

FIG. 5E(1) shows index 570, which is another example of location isanother example of a location index. Similar to index 560, index 570includes bins 552, subnet IDs 553, and start of bins 554. Index 570 alsoincludes bit code of avg. lat. 572, bit code of long. 574, bit code oflat. 576, and bit code of avg. long. 578. In other embodiments, index570 may contain other information and/or columns in addition to and/orinstead of that shown in FIG. 5E(1).

Similar to index 550, index 570 is an example of a geographic index,which corresponds to the examples of FIGS. 4A, 4B, 5B(6). Thecombination of index 420 and geographic index 570 form an example of theidentifier to location index 210, and defines an example of the mapping214 of FIG. 2. Bins 552, subnet IDs 553, and start of bins 554 werediscussed in conjunction with FIG. 5C(1).

In the example of index 570, instead of encoding each set of locationcoordinates (e.g., each having a longitude and latitude) as one number,each number was given a separate bit value.

Bit code of avg. lat. 572 contains the bit code for the average of thelatitudes of the bin. Bit code of long. 574 contains the bit code forthe average of the longitudes of the bin. Bit code of lat. 576 containsthe bit code of the latitudes of the bin. Bit code of long contains thebit code the longitudes of the bin. Each of the values in bit code ofavg. lat. 572, bit code of long. 574, bit code of lat. 576, and bit codeof avg. long. 578 have been encoded such that values that occur morefrequently require fewer bits.

FIG. 5E(2) shows an example of an index for converting the bit codes ofFIG. 5E(1) into numerical values. The index of FIG. 5E(2) may berepresented as a binary tree, for example, for a fast lookup. The leftcolumn list the bit codes used in index 570 and the right columnincludes the corresponding numerical values. Once one has located aparticular bit value for latitude or longitude of a particular subnet orof a particular bin of index 570, the bit code is looked up in the indexof FIG. 5E(2).

Method of Blocking Undesirable Packets

FIG. 6 is an embodiment of a method 600 of selecting and/or blocking aconnection. Method 600 blocks a connection by blocking packetsoriginating from a device the user or server does not want to connectto. In step 602, a first packet is received from a device. In step 604,the source and/or destination of the packet is read, and based on thesource or destination of the packet, the subnet is determined. Thesubnet may be determined by reading the first part of the networkaddress, which may be used as the subnet address. In step 606, adetermination is made as to whether communications with the device isexpected to be desirable. The determination may be made by determiningwhether the packet meets one or more criteria. In optional step 607, adetermination is made whether the subnet or address is one that iscritical for perform the desired tasks (e.g., playing a game). Forexample, the packet may originate from or destined to the server of thehost of the game. Possibly (e.g., to save the time of reading the entireaddress), any packet from or to subnet of a server (or other networkdevice or resource) that is critical to the task is automaticallyaccepted. There may be a whitelist of subnets and/or addresses fromwhich packets are always accepted. If the packet is determined not to beon the whitelist, the method proceeds to step 608 of step 606. Step 608,which involves determining an expected quality of the connection. Step608 may include an optional step 610.

In step 610, a list of subnets an/d or specific addresses, such asservers recommended by the service provider and/or a list of serversand/or subnets known to be problematic are checked to determine whetherto allow or block the packets. For example, the router may store a listof blacklisted subnets (and/or specific network addresses), which islist of subnets to always block. Alternatively, or additionally, theremay be a list of whitelisted subnets (and/or specific networkaddresses), and only those subnets or range of subnets are accepted.Alternatively, step 610 may be performed by the console rather than theby router or may not be performed at all. If the packet is from ordestined to a recommended server (or other device address, or subnet) orto a server that is not specifically unrecommended (or other deviceaddress, or subnet), method 600 continues with step 612.

In step 612, the hop count of the signal is determined (if the hop countcan be determined). If the hop distance is determinable, in step 614, adetermination is made as to whether the hop distance is acceptable. Ifthe hop count is acceptable, the method continues to step 616. In step616, a determination is made of the location of the device that sent thepacket. In step 618, a determination is made as to whether thegeographical location is an acceptable location. The determination maybe made based on how far away the location is, by whether theconnections is from the area in the past have been good, and/or bywhether the location has a good network. In step 620, if the location isacceptable, a determination is made for the ping time. In step 622, ifthe ping time is acceptable, the method proceeds to step 624. Similarly,retuning to step 607, is the packet is determined come from a criticaldevice, server, network resource, network address, or subnet, the methodproceeds to step 624, and in step 624, the packet is allowed to pass. Onthe other hand, if in step 610 it is determined that the server is noton the recommended list or is on a list of unrecommended devices,servers, addresses, subnets, if in step 614 it is determined that hopdistance is too long, if it is determined in step 618 that the locationof the device that sent the packet came from, or is destined to, anacceptable location, or if it is determined in step 622 that the pingtime is not acceptable, the method proceeds to step 626. In step 624,the packet is rejected.

In an embodiment, each of the steps of method 600 is a distinct step. Inanother embodiment, although depicted as distinct steps in FIG. 6, step602-620 may not be distinct steps. In other embodiments, method 600 maynot have all of the above steps and/or may have other steps in additionto or instead of those listed above. The steps of method 600 may beperformed in another order. Subsets of the steps listed above as part ofmethod 600 may be used to form their own method.

Method for Navigating Compressed Succint Tree

FIG. 7 is an example of the method 700 of converting a subnet addressinto a subnet identifier. In order to implement step 616 of method 600(FIG. 6), it may be desirable to convert the subnet address into alocation. To convert the subnet address into a location, first thesubnet address is converted into a subnet identifier. To convert thesubnet address into a subnet identifier, in may be desirable to navigatea compressed succinct tree. Method 700 involves navigating a compressedsuccinct tree.

In step 702, the root node of the compressed succinct tree is traversed,the next node is chosen based on the first digit of the subnet address.In step 704, a determination is made whether the current node haschildren or whether the last digit of the subnet address has beenreached. If the current node has children or if the end of the subnetaddress has been reached, the method 700 proceeds to step 706. In step706, if the nodes traversed match the subnet address, the subnet ID ofthe subnet that has been reached may computed, by subtracting the Rankof the node from the node number, which is the identifier of the subnet.

Returning to step 704, if the nodes traversed do not yet match thesubnet address or if there are still more digits to the subnet address,the method 700 proceeds to step 710, where a determination of whichbranch of the binary tree that is represented by the compressed succincttree to follow. Next in step 712, the node at the branch that wasdetermined in step 710 is traversed. In order to perform step 712, firstsub-step 714 is performed in which information about the current node isdetermined. For example, the rank of the current node is determined inorder to traverse to the node of one of the two children of the currentnode. Next, in sub-step 716 of step 712, the node number of the nextnode is computed, and after sub-step 716 and after step 712, the methodreturns to step 704, where a determination is made as to whether nodestraversed correspond to subnet of the packet received, restarting theloop of method 700.

In an embodiment, each of the steps of method 700 is a distinct step. Inanother embodiment, although depicted as distinct steps in FIG. 7, step702-716 may not be distinct steps. In other embodiments, method 700 maynot have all of the above steps and/or may have other steps in additionto or instead of those listed above. The steps of method 700 may beperformed in another order. Subsets of the steps listed above as part ofmethod 700 may be used to form their own method.

Method for Computing Rank of Current Node

FIG. 8A is an example of a method for implement step 714 of method 700or FIG. 7 in which information about the node is determined. Forexample, in step 714, the rank of the nodes is computed so that the nodenumber of at least on the children of the current node may bedetermined.

In step 802, the pre-calculated rank of the current bucket is read. Instep 804, the words between the beginning of the bin and the word havingthe current node does are determined. Next, in step 806, the popcountsof the words between the beginning of the bin and the word having thecurrent node are determined, such as be reading the save valuesrepresenting the popcounts. Next, in step 810, the popcounts of thewords between the beginning of the bin and the word having the currentnode are added to the rank of the bin. Next, in step 812, the pop countof the word having the node of interest is looked up. Then, in step 814,the sequence ID of the word having the node is determined (e.g., read orretrieved). In step 816, a determination of the bit sequence of the wordof interest is determined, based on the popcount and the sequence ID.Then, in step 818, the bits from the beginning of the word up until andincluding the node of interest are added together. Then, in step 820,the sum of the bits from the beginning of the word up until andincluding the node of interest are added to the sum of the rank and popcounts of the prior word of the bin to arrive at the rank of the node.

In an embodiment, each of the steps of method 800 is a distinct step. Inanother embodiment, although depicted as distinct steps in FIG. 8, step802-820 may not be distinct steps. In other embodiments, method 800 maynot have all of the above steps and/or may have other steps in additionto or instead of those listed above. The steps of method 800 may beperformed in another order. Subsets of the steps listed above as part ofmethod 800 may be used to form their own method.

Method of Determining Next Node to Traverse

FIG. 8B shows an example of a method for implementing step 716 of method700 (FIG. 7). In step 822, a determination of whether to traverse to theright child of the current node or the left child of the current node.For example, if the next digit in the subnet address is 1 the methodtraverses to the left child of the current node and the method proceedsto step 824. At step 824, the formula LeftChild(m)=2Rank(m) is computed.Returning to step 822, if the next digit of the subnet address is a 0,the method traverses to the right child of the current node, and themethod proceeds to step 826. At step 826, the formulaRightChild(m)=2Rank(m)+1 is computed.

In an embodiment, each of the steps of method of step 714 is a distinctstep. In another embodiment, although depicted as distinct steps in FIG.8, step 822-826 may not be distinct steps. In other embodiments, themethod implementing of the step 714 may not have all of the above stepsand/or may have other steps in addition to or instead of those listedabove. The steps of method of implementing step 714 may be performed inanother order. Subsets of the steps listed above as part of method ofimplementing step 714 may be used to form their own method.

Method of Determining Bit Sequence of Current Word

FIG. 8C shows an embodiment of method for implementing step 816 (FIG.8A) of the method for implement step 714 of method 700 (FIG. 7). Inoptional step 834, a determination of the place P of the mostsignificant digit of the representation of the bit sequence is thedetermined, based on the popcount of the word. For example, P=thepopcount of the current word (step 834 is optional because the popcountmay be used as the value of the highest possible place without expresslysetting the P to the popcount, and the popcount may be retrieved beforestep 716). In optional step 836, the highest possible value H of themost significant digit is determined. For example, H may be set to thenumber of digits in the word minus 1 is the highest possible value forthe first digit of the representation of the bit sequence. However, thenumber of bits in each word is already known and therefore may not needto be expressly determined each time method 716 is implemented. In step838, C(H,P) is computed. In step 842, a determination is made whetherSeq. ID is greater or smaller than C(H,P). If the Seq. ID is smallerthan C(H,P), then the leading digit has not been found and, ins step844, H is decremented by 1 or H=H−1, and the method returns to step 838to determine the value of the current digit. Returning to step 842, ifthe Seq. ID is greater than or equal to C(H,P), then the value of thecurrent digit is H, and the method proceeds to step 846, if P=1, thenall the elements of the representation of the bit sequence has beendetermined and step 716 concludes. If P is greater than 1, then themethod proceeds to step 848, where the Seq. ID is decremented by C(H,P)or Seq. ID=Seq. ID—C(H,P), and then P is decremented by 1 or P=P−1 iscomputed. After step 848, the method proceeds to step 844, where H isreplaced with H−1, and the search of the next most significant digit ofthe representation of the bit sequence is started.

In an embodiment, each of the steps of method of step 716 is a distinctstep. In another embodiment, although depicted as distinct steps in FIG.8, step 834-848 may not be distinct steps. In other embodiments, themethod implementing of the step 816 may not have all of the above stepsand/or may have other steps in addition to or instead of those listedabove. The steps of method of implementing step 816 may be performed inanother order. Subsets of the steps listed above as part of method ofimplementing step 816 may be used to form their own method.

Method for Implementing a Sub Net to Location Index

FIG. 8D is a method of implementing part of step 616 and step 618 ofmethod 600. The method of FIG. 8D is an embodiment of a method ofimplementing the identifier to location index 210 and/or mapping 216(FIG. 2).

In step 851, the geographic index coordinates (that is, the subnet IDsused by the location index) are determined based on the subnet ID foundin the binary tree, such as by looking up the subnet IDs in an indexsuch as the index 400 b of FIG. 4B. In step 852, the subnet IDs of startthe bins of the location index are searched until the bin having thesubnet ID of interest are found. In step 854, the subnet IDs in the binof interest are searched until the subnet of interest is found. In step856, optionally, the bit code for the average geographic coordinates ofthe bin of interest are retrieved, and then the average geographiccoordinates of the subnets of the bin are determined (e.g., looked up inan index or tree, such as a binary tree) based on the bit coderetrieved. In step 858, the global location coordinates of the subnet ofinterest are determined. In step 858, the bit code for the coordinatesof the subnet of interest are retrieved and the geographic coordinatesof the subnet are determined (e.g., looked up in an index or tree, suchas a binary tree) based on the bit code retrieved. In an embodiment inwhich the geographic coordinates retrieved based on the bit coderetrieved are the global coordinates, step 858 if complete. In anembodiment in which the geographic coordinates of the subnet of interestare the local bin coordinates (the global geographic coordinates minusthe average of the location coordinates of the subnets of the bin), theglobal location coordinates are computed from the average locationgeographic coordinates of the bin and within-bin location coordinateassociated with the geographic index coordinates of the subnet ofinterest, such as by adding average location coordinates of the bin tothe within-bin location coordinate of the subnet ID (the averagelocation coordinates of the bin may be replaced with another offset). Instep 860, the distance from the router to the subnet of interest isdetermined. In step 862 (or step 618 of method 600 of FIG. 6), adetermination of whether the distance is acceptable is made. For theexample, a determination is made whether the distance is larger than athreshold distance.

In an embodiment, each of the steps of method of steps 616 and 618 aredistinct steps. In another embodiment, although depicted as distinctsteps in FIG. 8, step 851-862 may not be distinct steps. In otherembodiments, the method implementing of the steps 616 and 618 may nothave all of the above steps and/or may have other steps in addition toor instead of those listed above. The steps of method of implementingsteps 616 and 618 may be performed in another order. Subsets of thesteps listed above as part of method of implementing step 616 and 618may be used to form their own method.

An Example of Hardware for Implementing the Method of this Specification

FIG. 9 shows an example of a router 900. The router may include one ormore network interface modules, an optional packet switch, a processorsystem, and memory. In other embodiments, router 900 may includeadditional components and/or may not include all of the componentslisted above.

The network interface modules may include a physical interface to anetwork, such as the Internet. The network interface module may be anetwork card or other network interface module with similar functions.The network interface module processes incoming packets, determineswhere to send the incoming packets and forwards the incoming packets tothe optional packet switch. The network interface module also receivespackets from the optional packet switch and forwards the packets toanother device in the network.

The optional packet switch (which is optional) connects the networkinterfaces to one another and to the processor. Packets travel from onenetwork interface module to the optional packet switch. Packets in theoptional packet switch may travel from the optional packet switch to theprocessor, to a different network interface module, or back to the samenetwork interface. The optional packet switch may be a hardware switchor may be a shared memory. If the optional packet switch is a sharedmemory, the packets may be sent to the optional packet switch andretrieved from the optional packet switch rather than the optionalpacket switch sending packets to other components.

The processor receives packets from the optional packet switch,determines the next destination for the packets, and then returns thepackets to the optional packet switch to be forwarded to a networkinterface module. When a group of packets originate from the same sourcethat are headed for the same destination, one packet from the group maybe processed by the processor, and the remaining packets may beprocessed by the network interface without being sent to the processor,and the network interface module is configured to determine how toprocess other packets of the group based on the packet from the groupthat was processed by the processor. The processor system may includeone or more processors. The processor system may include an interface toa console, such as personal computer or game console.

The memory system may store information and instructions related forimplementing protocols that determine whether to allow a packet to passfrom one network and/or device to another and/or what device in thenetwork to forward the packet (e.g., based on hop distance). Thealgorithm for filter out packets from locations that are likely not tohave a good connection and the compression algorithm may be sent, via aninterface to the memory system accessible by a console, which may be runby the processor system of the router.

FIG. 10 shows an example of a network interface module 1000. The networkinterface module may include a controller, a forwarding engine, and anoutput queue. In other embodiments, network interface module 1000 mayinclude additional components and/or may not include all of thecomponents listed above.

The forwarding engine determines where to forward the packets, and thensends the packet to the optional packet switch, where the packets areforwarded to the destination determined by the forwarding engine. Theoutput queue is a queue of packets from the optional packet switch,which are waiting to be sent by the controller to the next device in thenetwork. The controller controls the forwarding engine and output queue.The controller may have a memory for storing addresses of devices.

FIG. 11 shows a block diagram of a console 1100 used in the system ofFIG. 1.

The console 1100 may include output system 1102, input system 1104,memory system 1106, processor system 1108, communications system 1112,and input/output device 1114. In other embodiments, console 1100 mayinclude additional components and/or may not include all of thecomponents listed above.

Console 1100 is an example of system that may be used for a server or auser system. The user system may be a laptop, tablet, personal computer,mobile phone, server, game console and/or other computing device.

Output system 1102 may include any one of, some of, any combination of,or all of a monitor system, a handheld display system, a printer system,a speaker system, a connection or interface system to a sound system, aninterface system to peripheral devices and/or a connection and/orinterface system to a computer system, intranet, and/or internet, forexample. Output system 1102 may send communications, via the router, toother systems connected to the network.

Input system 1104 may include any one of, some of, any combination of,or all of a keyboard system, a mouse system, a track ball system, atrack pad system, buttons on a handheld system, a scanner system, amicrophone system, a connection to a sound system, and/or a connectionand/or interface system to a computer system, intranet, and/or internet(e.g., IrDA, USB), for example. Input system 1104 may receivecommunications, via the router, from other systems connected to thenetwork.

Memory system 1106 may include, for example, any one of, some of, anycombination of, or all of a long term storage system, such as a harddrive; a short term storage system, such as random access memory; aremovable storage system, such as a floppy drive or a removable drive;and/or flash memory. Memory system 1106 may include one or more machinereadable mediums that may store a variety of different types ofinformation. The term machine-readable medium is used to refer to anymedium capable carrying information that is readable by a machine. Oneexample of a machine-readable medium is a computer-readable medium.Another example of a machine-readable medium is paper having holes thatare detected that trigger different mechanical, electrical, and/or logicresponses. Memory system 1106 may store a browser and/or other interfacefor communication with the router.

Processor system 1108 may include any one of, some of, any combinationof, or all of multiple parallel processors, a single processor, a systemof processors having one or more central processors and/or one or morespecialized processors dedicated to specific tasks. Also, processorsystem 1108 may include one or more Digital Signal Processors (DSPs) inaddition to or in place of one or more Central Processing Units (CPUs)and/or may have one or more digital signal processing programs that runon one or more CPU.

Communications system 1112 communicatively links output system 1102,input system 1104, memory system 1106, processor system 1108, and/orinput/output system 1114 to each other. Communications system 1112 mayinclude any one of, some of, any combination of, or all of electricalcables, fiber optic cables, and/or means of sending signals through airor water (e.g., wireless communications), or the like. Some examples ofmeans of sending signals through air and/or water include systems fortransmitting electromagnetic waves such as infrared and/or radio wavesand/or systems for sending sound waves.

Input/output system 1114 may include devices that have the dual functionas input and output devices. For example, input/output system 1114 mayinclude one or more touch sensitive screens, which display an image andtherefore are an output device and accept input when the screens arepressed by a finger or stylus, for example. The touch sensitive screensmay be sensitive to heat and/or pressure. One or more of theinput/output devices may be sensitive to a voltage or current producedby a stylus, for example. Input/output system 1114 is optional and maybe used in addition to or in place of output system 1102 and/or inputdevice 1104. Input/output system may handle communications with othersystem in the network, via the router.

EXAMPLES OF EMBODIMENTS

Embodiment 1. A system comprising:

a processor system including one or more processors, and

a memory system, the memory system storing one or more machineinstructions, which when implement cause the processor system toimplement a method including at least

determining by a machine of the system whether a packet is from alocation that meets one or more predetermined criteria, the one or morepredetermined criteria being indicative of whether an acceptableconnection quality is obtainable;

if the determining determines that the one or more predeterminedcriteria are not met, blocking by the machine, the packet; and

if the determining determines that one or more predetermined criteriaare met, processing by the machine, the packet;

the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity of a destination, if the packet originated from within theparticular predefined vicinity of the destination, at least one of theone or more predetermined criteria are met, and unless there is anotherof the one or more predetermined criteria that is not met, the packet isallowed to pass, by the machine; and

if the packet originated from outside of the particular predefinedvicinity of the destination, the one or more predetermined criteria arenot met, and the packet is blocked by the machine.

Embodiment 2. A system comprising:

a processor system including one or more processors, and

a memory system, the memory system storing one or more machineinstructions, which when implement cause the processor system toimplement a method including at least

searching, by the system, for a host that hosts a given service;

determining, by a first machine, whether a packet, from a secondmachine, is from a location that meets one or more predeterminedcriteria, the one or more predetermined criteria being indicative ofwhether an acceptable connection quality is obtainable, the firstmachine having a processor system including one or more processors and amemory system;

if the determining determines that the one or more predeterminedcriteria are not met, blocking by the first machine, the packet;

if the determining determines that one or more predetermined criteriaare met, processing by the first machine, the packet;

the determining of whether the one or more predetermined criteria aremet including at least determining, by the first machine, whether thepacket originated from a location that is within a particular predefinedvicinity,

if the packet originated from within the particular predefined vicinity,at least one of the one or more predetermined criteria are met, andunless there is another of the one or more predetermined criteria thatis not met, the packet is allowed to pass, by the first machine; and

if the packet originated from outside of the particular predefinedvicinity, the one or more predetermined criteria are not met, and thepacket is blocked by the first machine,

as a result of the packet being blocked, the second machine ceasing tosend packets to the first machine.

Embodiment 3. The system of any of embodiments 1-19 or 1, wherein

the determining of whether the criterion is met including at least

determining whether, by the machine, a ping time is less than a giventhreshold;

if the ping time is less than the threshold, at least one of the one ormore predetermined criteria are met, and unless there is another of theone or more predetermined criteria are met, and unless there is anotherof the one or more predetermined criteria that is not met, the packet isallowed to pass, by the machine; and

if the ping time is greater than the threshold, at least one of the oneor more predetermined criteria is not met, and the packet is blocked bythe machine.

Embodiment 4. The system of any of embodiments 1-19 or 1, the systembeing a router.

Embodiment 5. The system of any of embodiments 1-19 or 1, the systembeing a server.

Embodiment 6. The system of any of embodiments 1-19 or 5, the serverbeing a host of an online game.

Embodiment 7. A system of any of embodiments 1-19 or 1, the methodfurther comprising

preventing, by the system, a user that is outside of the predefinedvicinity from joining a game by at least performing the method.

Embodiment 8. The system of any of embodiments 1-19 or 1, thedetermining of whether the packet originated from the location that iswithin the particular predefined vicinity including at least determininga location associated with a subnet by at least

determining, by the machine, a subnet identifier from an index thatstores an association between the subnet addresses and subnetidentifiers, and

determining, by the machine, a location based on the subnet identifierfrom an index that stores an association of subnet identifiers withlocations;

the index that stores the association between the subnet addresses andthe subnet identifiers being compressed, and the determining of thesubnet identifier from the index that stores the association between thesubnet addresses and the subnet identifiers, including at leastextracting the subnet identifier from the index that stores theassociation between the subnet addresses and the subnet identifierswhile the index that stores the associations between the subnetaddresses and the subnet identifiers is compressed.

Embodiment 9. A system comprising:

a processor system including one or more processors, and

a memory system, the memory system storing one or more machineinstructions, which when implement cause the processor system toimplement a method including at least

determining, by a machine of the system, whether a packet is from alocation that meets one or more predetermined criteria, the one or morepredetermined criteria being indicative of whether an acceptableconnection quality is obtainable, the machine having a processor systemincluding one or more processors and a memory system;

if the determining determines that at least one of the one or morepredetermined criteria are not met, blocking by the machine, the packet;and

if the determining determines that the one or more predeterminedcriteria are met, processing by the machine, the packet;

the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity,

if the packet originated from within the particular predefined vicinity,at least one of the one or more predetermined criteria are met, andunless there is another of the one or more predetermined criteria thatis not met, the packet is allowed to pass, by the machine; and

if the packet originated from outside of the particular predefinedvicinity, the one or more predetermined criteria are not met, and thepacket is blocked by the machine;

the determining of whether the packet originated from the location thatis within the particular predefined vicinity including at leastdetermining a location associated with a subnet by at least

determining, by the machine, a subnet identifier from an index thatstores an association between the subnet addresses and subnetidentifiers, and

determining, by the machine, a location based on the subnet identifierfrom an index that stores an association of subnet identifiers withlocations;

the index that stores the association between the subnet addresses andthe subnet identifiers being compressed, and the determining of thesubnet identifier from the index that stores the association between thesubnet addresses and the subnet identifiers, including at leastextracting the subnet identifier from the index that stores theassociation between the subnet addresses and the subnet identifierswhile the index that stores the associations between the subnetaddresses and the subnet identifiers is compressed.

Embodiment 10. A system comprising:

a processor system including one or more processors, and

a memory system, the memory system storing one or more machineinstructions, which when implement cause the processor system toimplement a method including at least

determining, by a machine, whether a packet is from a location thatmeets one or more predetermined criteria, the one or more predeterminedcriteria being indicative of whether an acceptable connection quality isobtainable, the machine having a processor system including one or moreprocessors and a memory system;

if the determining determines that at least one of the one or morepredetermined criteria are not met, blocking by the machine, the packet;and

if the determining determines that the one or more predeterminedcriteria are met, processing by the machine, the packet;

the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity,

if the packet originated from within the particular predefined vicinity,at least one of the one or more predetermined criteria are met, andunless there is another of the one or more predetermined criteria thatis not met, the packet is allowed to pass, by the machine; and

if the packet originated from outside of the particular predefinedvicinity, the one or more predetermined criteria are not met, and thepacket is blocked by the machine;

the determining of whether the packet originated from the location thatis within the particular predefined vicinity including at leastdetermining a location associated with a subnet by at least

determining, by the machine, a subnet identifier from an index thatstores an association between subnet addresses and subnet identifiers,and determining, by the machine, a location based on a subnet identifierfrom an index that stores an association of subnet identifiers withlocations;

extracting the subnet identifier, the extracting of the subnetidentifier including at least navigating the index that stores theassociation between a subnet addresses and the subnet identifiers, basedon the subnet address, by at least computing, by the machine, a rank ofa current node and computing a value associated with a next node, thecomputing of the value associated with the next node including at least

computing, by the machine, twice the rank of the current node, if a nodeof interest is a first child of the current node, where twice the rankof the current node is the value associated with the next node and

computing, by the machine, twice the rank of the current node plus one,if the node of interest is a second child of the current node, wheretwice the rank of the current node plus one is the value associated withthe next node.

Embodiment 11. A system comprising:

a processor system including one or more processors, and

a memory system, the memory system storing one or more machineinstructions, which when implement cause the processor system toimplement a method including at least

determining, by a machine, whether a packet is from a location thatmeets one or more predetermined criteria, the one or more predeterminedcriteria being indicative of whether an acceptable connection quality isobtainable, the machine having a processor system including one or moreprocessors and a memory system;

if the determining determines that at least one of the one or morepredetermined criteria are not met, blocking by the machine, the packet;and

if the determining determines that the one or more predeterminedcriteria are met, processing by the machine, the packet;

the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity,

if the packet originated from within the particular predefined vicinity,at least one of the one or more predetermined criteria are met, andunless there is another of the one or more predetermined criteria is notmet, the packet is allowed to pass, by the machine; and

if the packet originated from outside of the particular predefinedvicinity, the one or more predetermined criteria are not met, and thepacket is blocked by the machine;

the determining of whether the packet originated from the location thatis within the particular predefined vicinity including at leastdetermining a location associated with a subnet by at least

determining, by the machine, a subnet identifier from an index thatstores an association between subnet addresses and subnet identifiers,and

determining, by the machine, a location based on the subnet identifierfrom an index that stores an association of subnet identifiers withlocations;

extracting the subnet identifier, the extracting of the subnetidentifier including at least computing a rank of the node associatedwith the subnet; and

determining a value of the subnet identifier based on the rank of thenode associated with the subnet.

Embodiment 12. The system of any of embodiments 1-19 or 8, the methodfurther comprising extracting the subnet identifier, the extractingincluding determining, by the machine, a sequence of bits that isassociated with a word, the word being associated with the subnet, thedetermining being based on an identifier of the sequence of bits and astored value representing how many bits are in the word that are set toa particular value.

Embodiment 13. A system comprising:

a processor system including one or more processors, and

a memory system, the memory system storing one or more machineinstructions, which when implement cause the processor system toimplement a method including at least

determining, by a machine, whether a packet is from a location thatmeets one or more predetermined criteria, the one or more predeterminedcriteria being indicative of whether an acceptable connection quality isobtainable, the machine having a processor system including one or moreprocessors and a memory system; if the determining determines that atleast one of the one or more predetermined criteria are not met,blocking, by the machine, the packet; and

if the determining determines that the one or more predeterminedcriteria are met, processing by the machine, the packet;

the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity,

if the packet originated from within the particular predefined vicinity,at least one of the one or more predetermined criteria are met, andunless there is another of the one or more predetermined criteria is notmet, the packet is allowed to pass, by the machine; and

if the packet originated from outside of the particular predefinedvicinity, the one or more predetermined criteria are not met, and thepacket is blocked by the machine;

the determining of whether the packet originated from the location thatis within the particular predefined vicinity including at leastdetermining a location associated with a subnet by at least

determining, by the machine, a subnet identifier from an index thatstores an association between subnet addresses and subnet identifiers,and

determining, by the machine, a location based on the subnet identifierfrom an index that stores an association of subnet identifiers withlocations;

extracting the subnet identifier, the extracting of the subnetidentifier including at least

determining, by the machine, a bucket corresponding to a node ofinterest, the node of interest being a node of a tree represented by theindex that stores the association between the subnet addresses and thesubnet identifiers;

retrieving, by the machine, a rank associated with the bucket;

determining, by the machine, a word within the bucket corresponding tothe node of interest;

determining, by the machine, words within the bucket based on a start ofthe bucket and the word corresponding to the node of interest;

retrieving, by the machine, a popcount for each word from the start ofthe bucket until the word corresponding to the node of interest, thepopcount being a count of all bits in the word that are set to aparticular value;

determining, by the machine, how many bits are set to the particularvalue that

(1) are in the word corresponding to the node of interest, and

(2) are associated with bit locations starting at a beginning of theword and ending at a bit associated with the node of interest;

determining, by the machine, a sum of

the rank associated with the bucket,

the popcount of each word from the start of the bucket to the wordassociated with the node of interest, and

the bits are set to the particular value that

(1) are in the word corresponding to the node of interest, and

(2) are associated with bit locations starting at a beginning of theword and ending at the bit associated with the node of interest.

Embodiment 14. A system comprising:

a processor system including one or more processors, and

a memory system, the memory system storing one or more machineinstructions, which when implement cause the processor system toimplement a method including at least

determining, by a machine, whether a packet is from a location thatmeets one or more predetermined criteria, the one or more predeterminedcriteria being indicative of whether an acceptable connection quality isobtainable, the machine having a processor system including one or moreprocessors and a memory system;

if the determining determines that at least one of the one or morepredetermined criteria are not met, blocking, by the machine, thepacket; and

if the determining determines that the one or more predeterminedcriteria are met, processing, by the machine, the packet;

the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity,

if the packet originated from within the particular predefined vicinity,at least one of the one or more predetermined criteria are met, andunless there is another of the one or more predetermined criteria is notmet, the packet is allowed to pass, by the machine; and

if the packet originated from outside of the particular predefinedvicinity, the one or more predetermined criteria are not met, and thepacket is blocked by the machine;

the determining of whether the packet originated from the location thatis within the particular predefined vicinity including at leastdetermining a location associated with a subnet by at least

determining, by the machine, a subnet identifier from an index thatstores an association between subnet addresses and subnet identifiers,and

determining, by the machine, a location based on the subnet identifierfrom an index that stores an association of subnet identifiers withlocations;

the index that stores the association of subnet identifiers withlocations being compressed, and the determining of the subnet identifierfrom the index that stores the association between the subnetidentifiers and locations, including at least

searching for the locations associated with the subnet identifiers inthe index that stores the association of subnet identifiers with thelocations, while the index that stores the association of subnetidentifiers with the locations is compressed.

Embodiment 15. A system comprising:

a processor system including one or more processors, and

a memory system, the memory system storing one or more machineinstructions, which when implement cause the processor system toimplement a method including at least

determining, by a machine, whether a packet is from a location thatmeets one or more predetermined criteria, the one or more predeterminedcriteria being indicative of whether an acceptable connection quality isobtainable, the machine having a processor system including one or moreprocessors and a memory system;

if the determining determines that at least one of the one or morepredetermined criteria are not met, blocking, by the machine, thepacket; and

if the determining determines that the one or more predeterminedcriteria are met, processing, by the machine, the packet;

the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity,

if the packet originated from within the particular predefined vicinity,at least one of the one or more predetermined criteria are met, andunless there is another of the one or more predetermined criteria is notmet, the packet is allowed to pass, by the machine; and

if the packet originated from outside of the particular predefinedvicinity, the one or more predetermined criteria are not met, and thepacket is blocked by the machine;

the determining of whether the packet originated from the location thatis within the particular predefined vicinity including, at least,determining a location associated with a subnet by at least

determining, by the machine, a subnet identifier from an index thatstores an association between subnet addresses and subnet identifiers,and

determining, by the machine, a location based on the subnet identifierfrom an index that stores an association of subnet identifiers withlocations; and

the index that stores the association of the subnet identifiers with thelocations, having the locations encoded with bit sequences, wherelocation coordinates that occur more frequently are encoded with bitshorter bit sequences than bit sequences representing locationcoordinates that occur less frequently, the method further including atleast

determining, by the machine, a bucket that stores information associatedwith a subnet identifier of interest by at least searching, by themachine, a collection of subnet identifiers characterizing buckets; and

determining, by the machine, a location within the bucket by at leastsearching within the bucket for the subnet identifier of interest.

Embodiment 16. A system comprising:

a processor system including one or more processors, and

a memory system, the memory system storing one or more machineinstructions, which when implement cause the processor system toimplement a method including at least

determining, by a machine, whether a packet is from a location thatmeets one or more predetermined criteria, the one or more predeterminedcriteria being indicative of whether an acceptable connection quality isobtainable, the machine having a processor system including one or moreprocessors and a memory system;

if the determining determines that at least one of the one or morepredetermined criteria are not met, blocking, by the machine, thepacket;

and if the determining determines that the one or more predeterminedcriteria are met, processing, by the machine, the packet;

if the packet originated from outside of the particular predefinedvicinity, the one or more predetermined criteria are not met, and thepacket is blocked by the machine;

the determining of whether the packet originated from the location thatis within the particular predefined vicinity including at least thedetermining of the location including at least determining a locationassociated with a subnet by at least

determining, by the machine, a location based on a subnet identifierfrom one or more indexes that store an association of subnet identifierswith location related information;

the one or more indexes that store the association of subnet identifierswith location related information being compressed, and the determiningof location based on the subnet identifier from the one or more indexesthat stores the association of the subnet identifiers with the locationrelated information, including at least searching the one or moreindexes while the one or more indexes are compressed.

Embodiment 17. The system of any of embodiments 1-19 or 1, wherein thedetermining of the location comprising determining a location associatedwith a subnet by at least determining, by the machine, a location basedon a subnet identifier from one or more indexes that store anassociation of subnet identifiers with location related information.

Embodiment 18. The system of any of embodiments 1-19 or 1, wherein thedetermining of whether the packet is from a location being performed ona packet-by-packet basis.

Embodiment 19. The system of any of embodiments 1-19 or 1, wherein thedetermining of whether the packet is from a location being performed onpackets from the same network, where some packets from that network areblocked and some packets from that network are allowed to pass, based onwhether an acceptable connection quality is obtainable.

ALTERNATIVES AND EXTENSIONS

Throughout this specification the role of the 1s and 0s can be switchedand/or substituted with any other pair of two values. In the succincttree, if the is are used to represent the leafs, the rank of a node thatis a leaf gives the leaf identifier and when navigating the succincttree, LeftChild(m)=2(m-Rank(m)) and RightChild(m)=2(m-Rank(m))+1.

Each embodiment disclosed herein may be used or otherwise combined withany of the other embodiments disclosed. Any element of any embodimentmay be used in any embodiment.

Although the invention has been described with reference to specificembodiments, it will be understood by those skilled in the art thatvarious changes may be made, and equivalents may be substituted forelements thereof without departing from the true spirit and scope of theinvention. In addition, modifications may be made without departing fromthe essential teachings of the invention.

1. A system comprising: a machine having a processor system includingone or more processors and a memory system; the memory system storingone or more machine instructions, which when invoked by the one or moreprocessors causes the processor to implement a method including atleast, determining by the machine whether a packet is from a locationthat meets one or more predetermined criteria, the one or morepredetermined criteria being indicative of whether an acceptableconnection quality is obtainable; if the determining determines that theone or more predetermined criteria are not met, blocking by the machine,the packet; and if the determining determines that the one or morepredetermined criteria are met, processing by the machine, the packet;the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity of a destination, if the packet originated from within theparticular predefined vicinity of the destination, at least one of theone or more predetermined criteria are met, and unless there is anotherof the one or more predetermined criteria that is not met, the packet isallowed to pass, by the machine; and if the packet originated fromoutside of the particular predefined vicinity of the destination, theone or more predetermined criteria are not met, and the packet isblocked by the machine.
 2. A system comprising: a first machine having aprocessor system including one or more processors and a memory system;the memory system storing one or more machine instructions, which wheninvoked by the one or more processors causes the processor system toimplement a method including at least, hosting, by the first machine, aservice; searching, by a second machine, for a host that hosts theservice; determining by the first machine whether a packet, from thesecond machine, is from a location that meets one or more predeterminedcriteria, the one or more predetermined criteria being indicative ofwhether an acceptable connection quality is obtainable; if thedetermining determines that the one or more predetermined criteria arenot met, blocking by the first machine, the packet; and if thedetermining determines that the one or more predetermined criteria aremet, processing by the first machine, the packet; the determining ofwhether the one or more predetermined criteria are met including atleast determining, by the first machine, whether the packet originatedfrom a location that is within a particular predefined vicinity, if thepacket originated from within the particular predefined vicinity, atleast one of the one or more predetermined criteria are met, and thereinunless there is another of the one or more predetermined criteria thatis not met, the packet is allowed to pass, by the first machine; and ifthe packet originated from outside of the particular predefinedvicinity, the one or more predetermined criteria are not met, andtherein the packet is blocked by the first machine, as a result of thepacket being blocked, the second machine ceasing to send packets to thefirst machine.
 3. The system of claim 1, wherein the determining ofwhether the one or more predetermined criteria are met including atleast determining whether, by the machine, a ping time is less than agiven threshold; if the ping time is less than the given threshold, atleast one of the one or more predetermined criteria are met, and unlessthere is another of the one or more predetermined criteria are met, andtherein unless there is another of the one or more predeterminedcriteria that is not met, the packet is allowed to pass, by the machine;and if the ping time is greater than the given threshold, at least oneof the one or more predetermined criteria is not met, and therein thepacket is blocked by the machine.
 4. The system of claim 1, the machinebeing a router.
 5. The system of claim 1, the machine being a server. 6.The system of claim 5, the server being a host of an online game.
 7. Thesystem of claim 1, the method further comprising: preventing, by themachine, a user that is outside of the particular predefined vicinityfrom joining a game.
 8. The system of claim 1, the determining ofwhether the packet originated from the location that is within theparticular predefined vicinity including at least determining a locationassociated with a subnet by at least determining, by the machine, asubnet identifier from an index that stores an association betweensubnet addresses and subnet identifiers, and determining, by themachine, the location the packet originated from, based on (1) thesubnet identifier from the index that stores the association of thesubnet identifiers with locations associated with the subnetidentifiers; and (2) the index that stores the association between thesubnet addresses and the subnet identifiers being compressed, and thedetermining of the subnet identifier from the index that stores theassociation between the subnet addresses and the subnet identifiers,including at least extracting the subnet identifier from the index thatstores the association between the subnet addresses and the subnetidentifiers while the index that stores the associations between thesubnet addresses and the subnet identifiers is compressed.
 9. A systemcomprising: a machine having a processor system including one or moreprocessors and a memory system; the memory system storing one or moremachine instructions, which when invoked by the one or more processorscauses the processor system to implement a method including at least,determining, by the machine, whether a packet is from a location thatmeets one or more predetermined criteria, the one or more predeterminedcriteria being indicative of whether an acceptable connection quality isobtainable; if the determining determines that at least one of the oneor more predetermined criteria are not met, blocking by the machine, thepacket; and if the determining determines that the one or morepredetermined criteria are met, processing by the machine, the packet;the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity, if the packet originated from within the particular predefinedvicinity, at least one of the one or more predetermined criteria aremet, and therein unless there is another of the one or morepredetermined criteria that is not met, the packet is allowed to pass,by the machine; and if the packet originated from outside of theparticular predefined vicinity, the therein the one or morepredetermined criteria are not met, and the packet is blocked by themachine; the determining of whether the packet originated from thelocation that is within the particular predefined vicinity including atleast determining a location associated with a subnet by at leastdetermining, by the machine, a subnet identifier from an index thatstores an association between subnet addresses and subnet identifiers,and determining, by the machine, a location based on the subnetidentifier from the index that stores the association of the subnetidentifiers with locations associated with the subnet identifiers; andthe index that stores the association between the subnet addresses andthe subnet identifiers being compressed, and the determining of thesubnet identifier, from the index that stores the association betweenthe subnet addresses and the subnet identifiers, including at leastextracting the subnet identifier from the index that stores theassociation between the subnet addresses and the subnet identifierswhile the index that stores the association between the subnet addressesand the subnet identifiers is compressed.
 10. A system comprising: amachine having a processor system including one or more processors and amemory system; the memory system storing one or more machineinstructions, which when invoked by the one or more processors causesthe processor system to implement a method including at least,determining, by the machine, whether a packet is from a location thatmeets one or more predetermined criteria, the one or more predeterminedcriteria being indicative of whether an acceptable connection quality isobtainable; if the determining determines that at least one of the oneor more predetermined criteria are not met, blocking by the machine, thepacket; and if the determining determines that the one or morepredetermined criteria are met, processing by the machine, the packet;the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity, if the packet originated from within the particular predefinedvicinity, at least one of the one or more predetermined criteria aremet, and therein unless there is another of the one or morepredetermined criteria that is not met, the packet is allowed to pass,by the machine; and if the packet originated from outside of theparticular predefined vicinity, the one or more predetermined criteriaare not met, and therein the packet is blocked by the machine; thedetermining of whether the packet originated from the location that iswithin the particular predefined vicinity including at least determininga location associated with a subnet by at least determining, by themachine, a subnet identifier from an index that stores an associationbetween subnet addresses and subnet identifiers, and determining, by themachine, a location based on the subnet identifier from the index thatstores the association of the subnet identifiers with locationsassociated with the subnet identifiers; extracting the subnetidentifier, the extracting of the subnet identifier including at leastnavigating the index that stores the association between the subnetaddresses and the subnet identifiers, based on the subnet address, by atleast computing, by the machine, a rank of a current node and computinga value associated with a next node, the computing of the valueassociated with the next node including at least computing, by themachine, twice the rank of the current node, if a node of interest is afirst child of the current node, where twice the rank of the currentnode is the value associated with the next node and computing, by themachine, twice the rank of the current node plus one, if the node ofinterest is a second child of the current node, where twice the rank ofthe current node plus one is the value associated with the next node.11. A system comprising: a machine having a processor system includingone or more processors and a memory system; the memory system storingone or more machine instructions, which when invoked by the one or moreprocessors causes the processor system to implement a method includingat least, determining, by the machine, whether a packet is from alocation that meets one or more predetermined criteria, the one or morepredetermined criteria being indicative of whether an acceptableconnection quality is obtainable; if the determining determines that atleast one of the one or more predetermined criteria are not met,blocking by the machine, the packet; and if the determining determinesthat the one or more predetermined criteria are met, processing by themachine, the packet; the determining of whether the one or morepredetermined criteria are met including at least determining, by themachine, whether the packet originated from a location that is within aparticular predefined vicinity, if the packet originated from within theparticular predefined vicinity, at least one of the one or morepredetermined criteria are met, and therein unless there is another ofthe one or more predetermined criteria is not met, the packet is allowedto pass, by the machine; and if the packet originated from outside ofthe particular predefined vicinity, the one or more predeterminedcriteria are not met, and therein the packet is blocked by the machine;the determining of whether the packet originated from the location thatis within the particular predefined vicinity including at leastdetermining a location associated with a subnet by at least determining,by the machine, a subnet identifier from an index that stores anassociation between subnet addresses and subnet identifiers, anddetermining, by the machine, a location based on the subnet identifierfrom the index that stores the association of the subnet identifierswith locations associated with the subnet identifiers; the determiningof the subnet identifier including at least extracting the subnetidentifier, the extracting of the subnet identifier including at leastcomputing a rank of a node associated with the subnet; and determining avalue of the subnet identifier based on the rank of the node associatedwith the subnet.
 12. The system of claim 8, the extracting includingdetermining, by the machine, a sequence of bits that is associated witha word, the word being associated with the subnet, the determining beingbased on an identifier of the sequence of bits and a stored valuerepresenting how many bits are in the word that are set to a particularvalue.
 13. A system comprising: a machine having a processor systemincluding one or more processors and a memory system; the memory systemstoring one or more machine instructions, which when invoked by the oneor more processors causes the processor system to implement a methodincluding at least, determining, by the machine, whether a packet isfrom a location that meets one or more predetermined criteria, the oneor more predetermined criteria being indicative of whether an acceptableconnection quality is obtainable; if the determining determines that atleast one of the one or more predetermined criteria are not met,blocking, by the machine, the packet; and if the determining determinesthat the one or more predetermined criteria are met, processing by themachine, the packet; the determining of whether the one or morepredetermined criteria are met including at least determining, by themachine, whether the packet originated from a location that is within aparticular predefined vicinity, if the packet originated from within theparticular predefined vicinity, at least one of the one or morepredetermined criteria are met, and therein unless there is another ofthe one or more predetermined criteria is not met, the packet is allowedto pass, by the machine; and if the packet originated from outside ofthe particular predefined vicinity, the one or more predeterminedcriteria are not met, and therein the packet is blocked by the machine;the determining of whether the packet originated from the location thatis within the particular predefined vicinity including at leastdetermining a location associated with a subnet by at least determining,by the machine, a subnet identifier from an index that stores anassociation between subnet addresses and subnet identifiers, anddetermining, by the machine, a location based on the subnet identifierfrom the index that stores the association of the subnet identifierswith a collection of locations; the determining of the subnet identifierincluding extracting the subnet identifier, the extracting of the subnetidentifier including at least  determining, by the machine, a bucketcorresponding to a node of interest, the node of interest being a nodeof a tree represented by the index that stores the association betweenthe subnet addresses and the subnet identifiers;  retrieving, by themachine, a rank associated with the bucket; determining, by the machine,a word within the bucket corresponding to the node of interest; thedetermining of the word including determining, by the machine, wordswithin the bucket based on a start of the bucket and the wordcorresponding to the node of interest; retrieving, by the machine, apopcount for each word from the start of the bucket until the wordcorresponding to the node of interest, the popcount being a count of allbits in the word that are set to a particular value; determining, by themachine, how many bits are set to the particular value that (1) are inthe word corresponding to the node of interest, and (2) are associatedwith bit locations starting at a beginning of the word and ending at abit associated with the node of interest; determining, by the machine, asum of the rank associated with the bucket, the popcount of each wordfrom the start of the bucket to the word associated with the node ofinterest, and the bits are set to the particular value that (1) are inthe word corresponding to the node of interest, and (2) are associatedwith the bit locations starting at the beginning of the word and theending at the bit associated with the node of interest.
 14. A systemcomprising: a machine having a processor system including one or moreprocessors and a memory system; the memory system storing one or moremachine instructions, which when invoked by the one or more processorscauses the processor system to implement a method including at least,determining, by the machine, whether a packet is from a location thatmeets one or more predetermined criteria, the one or more predeterminedcriteria being indicative of whether an acceptable connection quality isobtainable; if the determining determines that at least one of the oneor more predetermined criteria are not met, blocking, by the machine,the packet; and if the determining determines that the one or morepredetermined criteria are met, processing, by the machine, the packet;the determining of whether the one or more predetermined criteria aremet including at least determining, by the machine, whether the packetoriginated from a location that is within a particular predefinedvicinity, if the packet originated from within the particular predefinedvicinity, at least one of the one or more predetermined criteria aremet, and therein unless there is another of the one or morepredetermined criteria is not met, the packet is allowed to pass, by themachine; and if the packet originated from outside of the particularpredefined vicinity, the one or more predetermined criteria are not met,and therein the packet is blocked by the machine; the determining ofwhether the packet originated from the location that is within theparticular predefined vicinity including at least determining a locationassociated with a subnet by at least determining, by the machine, asubnet identifier from an index that stores an association betweensubnet addresses and subnet identifiers, and determining, by themachine, a location based on the subnet identifier from the index thatstores the association of the subnet identifiers with locationsassociated with the subnet identifiers;  the index that stores theassociation of the subnet identifiers with the locations associated withthe subnet identifiers being compressed, and  the determining of thesubnet identifier from the index that stores the association between thesubnet identifiers and the locations associated with the subnetidentifiers, including at least  searching for the locations associatedwith the subnet identifiers in the index that stores the association ofthe subnet identifiers with the locations associated with the subnetidentifiers, while the index that stores the association of the subnetidentifiers with the locations associated with the subnet identifiers iscompressed.
 15. A system comprising: a machine having a processor systemincluding one or more processors and a memory system; the memory systemstoring one or more machine instructions, which when invoked by the oneor more processors causes the processor system to implement a methodincluding at least, determining, by the machine, whether a packet isfrom a location that meets one or more predetermined criteria, the oneor more predetermined criteria being indicative of whether an acceptableconnection quality is obtainable; if the determining determines that atleast one of the one or more predetermined criteria are not met,blocking, by the machine, the packet; if the determining determines thatthe one or more predetermined criteria are met, processing, by themachine, the packet; the determining of whether the one or morepredetermined criteria are met including at least determining, by themachine, whether the packet originated from a location that is within aparticular predefined vicinity, if the packet originated from within theparticular predefined vicinity, at least one of the one or morepredetermined criteria are met, and therein unless there is another ofthe one or more predetermined criteria is not met, the packet is allowedto pass, by the machine; and if the packet originated from outside ofthe particular predefined vicinity, the one or more predeterminedcriteria are not met, and therein the packet is blocked by the machine;the determining of whether the packet originated from the location thatis within the particular predefined vicinity including, at least,determining a location associated with a subnet by at least determining,by the machine, a subnet identifier from an index that stores anassociation between subnet addresses and subnet identifiers, anddetermining, by the machine, the location that is within the particularpredefined vicinity, based on the subnet identifier from the index thatstores the association of the subnet identifiers with locationsassociated with the subnet identifiers; and the index that stores theassociation of the subnet identifiers with the locations associated withthe subnet identifiers, having the locations associated with the subnetidentifiers encoded with bit sequences, where location coordinates thatoccur more frequently are encoded with shorter bit sequences than bitsequences representing location coordinates that occur less frequently,the method further including at least  determining, by the machine, abucket that stores information associated with a subnet identifier ofinterest by at least searching, by the machine, a collection of subnetidentifiers characterizing buckets; and  determining, by the machine, alocation within the bucket by at least searching within the bucket forthe subnet identifier of interest.
 16. A system comprising: a machinehaving a processor system including one or more processors and a memorysystem; the memory system storing one or more machine instructions,which when invoked by the one or more processors causes the processorsystem to implement a method including at least, determining, by themachine, whether a packet is from a location that meets one or morepredetermined criteria, the one or more predetermined criteria beingindicative of whether an acceptable connection quality is obtainable; ifthe determining determines that at least one of the one or morepredetermined criteria are not met, blocking, by the machine, thepacket; if the determining determines that the one or more predeterminedcriteria are met, processing, by the machine, the packet; if the packetoriginated from outside of a particular predefined vicinity, the one ormore predetermined criteria are not met, and therein the packet isblocked by the machine; the determining of whether the packet originatedfrom the location that is within the particular predefined vicinityincluding at least the determining of the location including at leastdetermining a location associated with a subnet by at least determining,by the machine, a location based on a subnet identifier from one or moreindexes that store an association of subnet identifiers withlocation-related information; the one or more indexes that store theassociation of the subnet identifiers with the location-relatedinformation being compressed, and the determining of the locationassociated with the subnet, based on the subnet identifier from the oneor more indexes that stores the association of the subnet identifierswith the location-related information, including at least searching theone or more indexes while the one or more indexes are compressed. 17.The system of claim 1, wherein the determining of the locationcomprising: determining a location associated with a subnet by at leastdetermining, by the machine, a location based on a subnet identifierfrom one or more indexes that store an association of subnet identifierswith location-related information.
 18. The system of claim 1, whereinthe determining of whether the packet is from the location that meetsone or more predetermined criteria being performed on a packet-by-packetbasis.
 19. The system of claim 1, wherein the determining of whether thepacket is from the location that meets one or more predeterminedcriteria being performed on packets from the same network, where somepackets from the same network are blocked and some packets from the samenetwork are allowed to pass, based on whether the acceptable connectionquality is obtainable.
 20. A system comprising: a first machine having aprocessor system including one or more processors and a memory system;the memory system storing one or more machine instructions, which wheninvoked by the one or more processors causes the processor to implementa method including at least, determining by the first machine whether apacket is from a location that meets one or more predetermined criteria,the one or more predetermined criteria being indicative of whether anacceptable connection quality is obtainable; if the determiningdetermines that the one or more predetermined criteria are not met,blocking by the first machine, the packet; if the determining determinesthat the one or more predetermined criteria are met, processing by thefirst machine, the packet; and as a result of blocking the packet, thefirst machine ceasing to receive packets from a second machine that sentthe packet.
 21. The system of claim 20, wherein the determining ofwhether the one or more predetermined criteria are met including atleast determining, by the first machine, whether a hop count is lessthan a given threshold; if the hop count is less than the giventhreshold, at least one of the one or more predetermined criteria aremet, and therein unless there is another of the one or morepredetermined criteria are met, and unless there is another of the oneor more predetermined criteria is not met, the packet is allowed topass, by the first machine; and if the hop count is greater than thegiven threshold, at least of one or more predetermined criteria is notmet, and the packet is blocked by the first machine.
 22. The system ofclaim 20, wherein the determining of whether the one or morepredetermined criteria are met including at least determining whether,by the first machine, a ping time is less than a given threshold; if theping time is less than the given threshold, at least one of the one ormore predetermined criteria are met, and unless there is another of theone or more predetermined criteria are met, and unless there is anotherof the one or more predetermined criteria is not met, therein the packetis allowed to pass, by the first machine; and if the ping time isgreater than the given threshold, at least one of the one or morepredetermined criteria is not met, and therein the packet is blocked bythe first machine.
 23. The system of claim 20, the first machine being arouter.
 24. The system of claim 20, the first machine being a server.25. The system of claim 24, the server being a host of an online game.26. The system of claim 20, wherein the method further comprisespreventing, by the first machine, a user that is outside of a predefinedvicinity from joining a game.
 27. The system of claim 20, whereinblocking the packet includes not sending an acknowledgement of receiptof the packet.
 28. The system of claim 20, wherein blocking the packetincludes dropping the packet.
 29. The system of claim 28, wherein thefirst machine communicates via a protocol in which a dropped packet istreated as a bad connection, therein causing the ceasing of receipt ofthe packet.
 30. A system comprising: a first machine having a processorsystem including one or more processors and a memory system; the memorysystem storing one or more machine instructions, which when invoked bythe one or more processors causes the processor to implement a methodincluding at least, determining by the first machine whether a packet isfrom a location that meets one or more predetermined criteria, the oneor more predetermined criteria being indicative of whether an acceptableconnection quality is obtainable; if the determining determines that theone or more predetermined criteria are not met, blocking by the firstmachine, the packet; if the determining determines that the one or morepredetermined criteria are met, processing by the first machine, thepacket; and as a result of blocking the packet, the first machineceasing to receive packets from a second machine that sent the packet;wherein the determining of whether the one or more predeterminedcriteria are met including at least determining whether, by the firstmachine, a ping time is less than a given threshold; if the ping time isless than the given threshold, at least one of the one or morepredetermined criteria are met, and therein unless there is another ofthe one or more predetermined criteria are met, and unless there isanother of the one or more predetermined criteria is not met, the packetis allowed to pass, by the first machine; and if the ping time isgreater than the given threshold, at least of one or more predeterminedcriteria is not met, and therein the packet is blocked by the firstmachine.
 31. A system comprising: a first machine having a processorsystem including one or more processors and a memory system; the memorysystem storing one or more machine instructions, which when invoked bythe one or more processors causes the processor to implement a methodincluding at least, determining by the first machine whether a messageis from a location that meets one or more predetermined criteria, theone or more predetermined criteria being indicative of whether anacceptable connection quality is obtainable; if the determiningdetermines that the one or more predetermined criteria are not met,blocking by the first machine, the message; if the determiningdetermines that the one or more predetermined criteria are met,processing by the first machine, the message; and as a result ofblocking the message, the first machine ceasing to receive the messagefrom a second machine that sent the message.
 32. The system of claim 31,wherein blocking the message includes dropping the message.
 33. Thesystem of claim 32, wherein the first machine communicates via aprotocol in which a dropped packet is treated as a bad connection,therein causing the ceasing of receipt of further packets.